Full text of "Title 24, Part 3, 2010 California Electrical Code"

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California Code of Regulations
Title 24, Part 3

i California Building Standards Commission
Based on 2008 National Electrical Code®

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2011

California Code of Regulations
Title 24, Part 3

Galifornia Building Standards Gommission
Based on 2008 National Electrical Code®

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EFFECTIVE
JANUARY 1,2011

(For Errata and Supplemenis, sea History NoleAppendixJ

Portions of this publication are reproduced with permission from the National Electrical Code"", 2008
edition, copyright © 2007 National Fire Protection Association, Quincy, MA 02269. AH rights reserved.
No portions of NEC® material may be reproduced except with permission of the National Fire
Protection Association.

ISBN 9781557016843

National Fire Protection Association

1 Batterymarch Park (P.O. Box 9146)

Quincy, MA 02269-9959

Held by

California Building Standards Commission

2525 Natoma Park Drive, Suite 130

Sacramento, CA 95833-2936

Printed in The United States

Published and Printed by BNi Publications^ Inc

National Electrical Code'' and ^EC^ are registered trademarks of the National Fire Protection

Association, Inc, Quincy, MA.

2010 California Electrical Code

Preface

This document is the 3rd of 12 Parts of the official triennial compilation and publication of the
adoptions, amendments and repeal of administrative regulations to California Code of Regulations, Title
24, also referred to as the California Building Standards Code, This Part is known as the California
Electrical Code and incorporates, by adoption, the 2008 edition of the National Electrical Code of the
National Fire Protection Association with the California amendments

The California Building Standards Code is published in its entirety every three years by order of the
California legislature, with supplements published in intervening years. The California legislature
delegated authority to various State agencies, boards, commissions and departments to create building
regulations to implement the State's statutes. These building regulations or standards, have the same
force of law, and take effect 180 days after their publication unless otherwise stipulated. The California
Building Standards Code applies to occupancies in the State of California as annotated.

A city, county or city and county may establish more restrictive building standards reasonably necessary
because of local climatic, geological or topographical conditions. Findings of the local condition(s) and
the adopted local building standard(s) must be filed with the California Building Standards Commission
to become effective and may not be effective sooner than the date filed with the Califomia Building
Standards Commission and in no case sooner than the effective date of this edition of California
Building Standards Code, Local building standards that were adopted and applicable to previous
editions of the California Building Standards Code do not apply to this edition without appropriate
adoption and the required filing.

To familiarize yourself with the format of this code, it is suggested that users review the following
contents:

• How To Distinguish Model Code Language From Califomia Amendments

• Matrix Adoption Tables, located at the beginning of each chapter.

Should you find publication (e.g., typographical) errors or inconsistencies in this code or wish to offer
comments toward improving its format, please address your comments to:

Califomia Building Standards Commission

2525 Natomas Park Drive, Suite 130

Sacramento, CA 95833-2936

Phone: (916)263-0916
FAX: (916)263-0959

Web Page: www.bsc.ca.gov

2010 Califomia Electrical Code

Acknowledgement

The 2010 California Building Standards Code (Code) was developed through the outstanding
collaborative efforts of the Department of Housing and Community Development, the Division of
State Architect, the Office of the State Fire Marshal, the Office of Statewide Health Planning and
Development, the California Energy Commission, and the Building Standards Commission
(Commission).

This collaborative effort included the assistance of the Commission's Code Advisory Committees and
many other volunteers that worked tirelessly to assist the Commission in the production of this Code.

Governor Arnold Schwarzenegger

Members of the Building Standards Commission

Acting Secretary Tom Sheehy - Chair

Isam Hasenin - Vice-Chair Christina Jamison

James Barthman Stephen Jensen f^U

Craig Dailey Michael Par avagna

Susan Dowty Richard Sawhill

Tony Hoffman Steven Winkel

David Walls - Executive Director
Thomas Morrison - Deputy Executive Director

For questions on California state agency amendments; please refer to the contact list on the following page.

2010 California Electrical Code

California Code ofRegulationSj Title 24
California Agency Information Contact List

California Energy Commission

Energy Hotline (800) 772-3300

or (916) 654-5106
Building Efficiency Standards
Appliance Efficiency Standards
Compliance Manual / Fornns

California State Lands Commission

Marine Oil Terminals (562) 499-6317

California State Library

Resources and Information (916) 654-0261

Government Publication Section (916) 654-0069

Corrections Standards Authority

Local Adult Jail Standards (916) 324-1 914

Local Juvenile Facility Standards (916) 324-1914

Department of Consumer Affairs - Acupuncture
Board

Office Standards (916) 445-3021

Department of Consumer Affairs - Board of
Pharmacy

Pharmacy Standards ) (916)574-7900

Department of Consumer Affairs - Bureau of
Barbering And Cosmetology

Barber and Beauty Shop and (916) 574-7570

College Standards (800)952-5210

Department of Consumer Affairs —

Bureau of Home Furnishings and Thermal insulation

Insulation Testing Standards (916) 574-2041

Department of Consumer Affairs - Structural Pest
Control Board

Structural Standards (800)737-8188

(916)561-8708
Department of Consumer Affairs - Veterinary Medical
Board

Veterinary Hospital Standards (916) 263-2610

Department of Food and Agriculture

Meat & Poultry Packing Plant

Standards (916) 654-1447

Dairy Standards (916)654-1447

Department of Public Health

Organized Camps Standards (916)449-5661

Public Swimming Pools Standards (916) 449-5693

Asbestos Standards (510) 620-2874

Department of Housing and Community
Deyelopment

Residential - Hotels, Motels, Apartments,
Single-Family Dwellings (916)445-9471

Permanent Structures in Mobilehome
and Special Occupancy Parks (916) 445-9471

Factory-Built Housing, Manufactured
Housing and Commercial Modular .... (916) 445-3338

Mobile Homes - Permits & Inspections

Northern Region (916) 255-2501

Southern Region (951) 782-4420

Employee Housing Standards (916) 445-9471

Department of Water Resources

Gray Water Installations Standards........ (916) 651-9667

Diyjsion of the State Architect - Access Compliance

Access Compliance Standards (916) 445-8100

DiyJsion of the State Architect - Structural Safety

Public Schools Standards (916) 445-8100

Essential Services Building Standards... (916) 445-8100
Community College Standards (916) 445-81 00

Diyision of the State Architect - State Historical
Building Safety Board

Alternative Building Standards (916)445-8100

Office of Statewide Health Planning and Deyelopment

Hospital Standards (916) 440-8409

Skilled Nursing Facility Standards (916)440-8409

Clinic Standards (916) 440-8409

Pemiits (916)440-8409

Office of The State Fire Marshal

Code Development and Analysis (916) 445-8200

Fire Safety Standards (916)445-8200

Fireplace Standards (916) 445-8200

Day Care Centers Standards (916) 445-8200

Exit Standards (916)445-8200

2010 California Electrical Code

How to Distinguish Between Model Code Language

and
California Amendments

To distinguish between model code language and the incorporated California amendments, including
exclusive California standards, California amendments will appear in italics.

Symbols in the margins indicate the status of code changes as follows:

[SFM] This symbol identifies which State agency(s), by its "acronym", has amended a section of the
model code. For a complete listing of the State agency acronyms, see the Application Section
within Chapter 1 .

A This symbol indicates a California amendment has been made to the model code.

This symbol indicates that a change has been made to a California amendment.

-— ^ This symbol indicates deletion of California language.

NOTATIONS USED IN THE NA TIONAL ELECTRICAL CODE

The following notation appears in the National Electrical Code to aid the user:

Shaded text inciicate^'thatUhe^^^^ the previous edition. The user

should inspect this text carefully, as some requirements may have been changed.

I A vertical line in the margin indicates an entirely new article.

2010 California Electrical Code

CONTENTS

ARTICLE

C 89 General Code Provisions 70-1

A 90 Introduction 70-21

Chapter 1 General

100 Definitions 70-24

I General 70-^4

n Over 600 Volts, Nominal 70-31

110 Requirements for Electrical Installations 70-32

I General 70-32

n 600 Volts, Nominal, or Less 70-36

ffl Over 600 Volts, Nominal 70-38

IV Tunnel Installations over 600 Volts, Nominal 70-40

V Manholes and other Electrical Enclosures

Intended for Personnel Entry, All Voltages 70-41

Chapter 2 Wuing and Protection

200 Use and Identification of Grounded Conductors 70-43

210 Branch Circuits 70-45

I Gaieral Provisions 70-45

n Branch-Circuit Ratings 70-49

m Required Outlets 70-52

215 Feeders 70-55

220 Branch-Circuit, Feeder, and Service Calculations 70-57

I General 70-57

n Branch Circuit Load Calculations 70-58

in Feeders and Service Load Calculations 70-60

IV Optional Feeder and Service Load Calculations 70-62

V Farm Load Calculations 70-66

225 Outside Branch Circuits and Feeders 70-67

I General 70-67

E More Than One Building or Other Stmcture 70-70

m Over 600 Volts 70-72

230 Services , 70-^3

I General 70-73

n Overhead Service-I>op Conductors 70-74

in Underground Service-Lateral Conductors 70-75

IV Service-Entrance Conductors 70-76

V Service Equipment — General 70-78

VT Service Equipment — E)isconnecting Means 70-78

Vn Service Equipment — Overcurrent Protection 70-80

Vm Services Exceeding 600 Volts, Nominal 70-81

240 Overcurrent Protection 70-83

IGeneral 70-83

n Location ...70-86

m Enclosures 70-90

IV Disconnecting and Guarding 70-90

VPlug Fuses, Fuseholders, and Adapters 70-90

VI Cartridge Fuses and Fuseholders 70-91

vn Circuit Breakers 70-91

VTH Supervised Industrial Installations 70-92

DC Overcurrent Protection Over 600 Volts, Nominal 70-93

ARTICLE

250 Grounding and Bonding 70-94

IGeneral 70-94

n System Grounding 70-97

in Grounding Electrode System and

Grounding Electrode Conductor .^.....^ 70-104

IV Enclosure, Raceway, and Service Cable ^t^ecims 70-109

VBonding S.. '...:...... 70-109

VI Equipment Grounding and Equipment

Grounding Conductors 70-1 13

vn Methods of Equipment Grounding 70-117

vm Direct-Current Systems 70-120

DC Instruments, Meters, and Relays 70-121

X Grounding of Systems and Circuits of

1 kV and Over (High Voltage) 70-121

280 SurgeAn:esters,ov^lfc¥ 70-123

IGeneral 70-123

n Installation 70-124

in Connecting Surge Arresters 70-124

285 ^igerl^^o^(^eDe^^es;(SPDs)i^lkV<arl^^ 70-124

IGeneral 70-124

n Installation 70-125

m Connecting SPJDs 70-125

Chapter 3 Wiring Methods and Materials

300 Wiring Methods 70^126

I General Requirements 70-126

n Requirements for Over 600 Volts, Nominal 70-136

310 Conductors for General Wiring 70-138

312 Cabinets, Cutout Boxes, and Meter Socket Enclosures 70-164

I Installation 70-164

n Construction Specifications 70-165

314 Outlet, Device, Pull, and Junction Boxes;

Conduit Bodies; Fittings; and Handhole Enclosures 70-167

I Scope and General 70-167

n Installation 70-168

ni Constmction Specifications 70-174

IV Pull and Junction Boxes for Use on

Systems Over 600 Volts, Nominal 70-175

320 Amiored Cable: Type AC 70-175

IGeneral ■ 70-175

n Installation 70-175

in Construction Specifications 70-177

322 Flat Cable Assemblies: Type FC 70-177

ICjeneral 70-177

n Installation 70-177

m Constmction 70-178

324 Flat Conductor Cable: Type FCC 70-178

IGeneral 70-178

ninstallation 70-178

mConstruction 70-180

2010 California Electrical Code

70-ix

CONTENTS

ARTICLE

326 Integrated Gas Spacer Cable: Type IGS ..70-180

I General 70-180

n Installation 70-180

ni Construction Specifications 70-181

328 Medium Voltage Cable: Type MV 70-181

I General 70-181

n Installation 7Ckl81

in Construction Specifications 70-182

330 Metal-Clad Cable: Type MC 70-182

I General 70-182

n Installation : 70-182

m Construction Specifications 70-183

332 Mineral-Insulated, Metal-Sheathed Cable: Type MI 70-184

I General 70-184

n Installation 70-184

ni Construction Specifications 70-185

334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS 70-185

I General 70-185

n Installation 70-185

in Construction Specifications 70-187

336 Power and Control Tray Cable: Type TC 70-188

IGeneral 70-188

n Installation 70-188

ni Construction Specifications 70-188

338 Service-Entrance Cable: Types SE and USE.. 70-189

IGeneral 70-189

n Installation 70-189

mConstmction 70-190

340 Underground Feeder and Branch-Circuit Cable: TypeUF 7(^190

IGeneral 70-190

n Installation 70-190

m Construction Specifications 70-191

342 Memiediate Metal Conduit: Type MC 70-191

IGeneral 70-191

n Installation 70-191

ni Construction Specifications 70-192

344 Rigid Metal Conduit: Type RMC 70-192

IGeneral 70-192

n Installation 70-193

nt Construction Specifications 70-194

348 Flexible Metal Conduit: Type FMC 70-194

IGeneral : 70-194

n Installation 70-195

350 Liquidtight Flexible Metal Conduit: Type LFMC 70-196

IGeneral 70-196

n Installation 70-196

m Construction Specifications 70-197

352 Rigid Polyvinyl Chloride Conduit: Type PVC 70-197

IGeneral 7(^197

n Installation 70-197

HI Construction Specifications 70-200

ARTICLE

353 High Density Polyethylene Conduit: Type HDPE Conduit 70-200

IGeneral 70-200

n Installation 70-200

ni Construction Specifications 70-201

354 Nonmetallic Underground Conduit with Conductors: TypeNUCC 70-201

IGeneral 70-201

n Installation 70-201

in Construction Specifications 70-202

355 R^nlbipeaThmmsettiM'E^laCp 70-203

I. General 70-203

n. Installation 70-203

DI. Construction Specifications 70-204

356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC 70-205

IGeneral 70-205

n Installation , 70-206

ni Construction Specifications 70-207

358 Electrical Metallic Tubing: Type EMT 70-207

IGeneral 70-207

n Installation 70-207

in Construction Specifications 70-208

360 Flexible Metallic Tubing: Type FMT 70-208

IGeneral 70-208

n Installation 70-209

m Construction Specifications 70-209

362 Electrical NonmetalHc Tubing: Type ENT 70-210

IGeneral 70-^10

n Installation 70-210

in Construction Specifications 70-211

366 Auxiliary Gutters 70-212

IGeneral 70-212

ninstaUation 70-212

ni Construction Specifications 70-213

368 Busways ..; 70-214

I General Requirements 70-214

n Installation 70-214

mConstiuction 70-215

IV Requirements for Over 600 Volts, Nominal 70-216

370 Cablebus 70^16

372 Cellular Concrete Floor Raceways 70-217

374 Cellular Metal Floor Raceways 70-218

IlnstaUation 70-219

n Constmction Specifications 70-219

376 Metal Wireways 70-219

IGeneral 70-219

n Installation 70-219

m Construction Specifications 70-220

378 Nonmetallic Wireways 70-221

IGeneral 70^21

n Installation 70-221

in Construction Specifications 70-222

380 Multioutlet Assembly 70-222

382 Nonmetallic Extensions 70-222

IGeneral 70-222

n Installation 70-223

ni, C<Histmotioti Specifications (concealable Notimetallic
E^tensiofisoMy)..!! ....^... „. \ 70-224

384 Strut-Type Channel Raceway 70-224

IGeneral 70-224

ninstaUation 70-224

ni Constmction Specifications 70-225

70-x

2010 California Electrical Code

CONTENTS

ARTICLE

386 Surface Metal Raceways 70-226

I General 70-226

n Installation 70-226

in Constmction Specifications 70-226

388 Surface Nonmetallic Raceways 70-227

IGeneral 70-227

n Installation 70-227

HI Constmction Specifications 70-227

390 Underfloor Raceways 70-228

392 Cable Trays ; 70-229

394 Concealed Knob-and-Tube Wiring 70-235

IGeneral 70-235

n Installation 70-236

ni Constmction Specifications 70-236

396 Messenger Supported Wiring 70-237

IGeneral 70-^37

n Installation 70-237

398 Open Wiring on Insulators 70-237

IGeneral 70^37

n Installation 70-238

in Constmction Specifications 70-239

Chapter 4 Equipment for General Use

400 Flexible Cords and Cables 70-240

IGeneral 70^40

n Constmction Specifications 70-249

m Portable Cables Over 600 Volts, Nominal 70-250

402 Fixture Wires 70-251

404 Switches 70-^55

I Installation 70-255

n Constmction Specifications 70-258

406 Receptacles, Cord Connectors, and Attachment Plugs (Caps) 70-258

408 Switchboards and Panelboards 70-262

IGeneral 70-262

n Switchboards 70-263

m Panelboards 70-263

rV Constmction Specifications '. 70-264

409 Industrial Control Panels 70-265

IGeneral 70-^65

n Installation 70-266

in Constmction Specifications 70-266

410 Luminaires, Lampholders, and Lamps 70-267

IGeneral : 70-267

n Luminaire Locations 70-268

ni Provisions at Luminaire Outlet Boxes, Canopies, and Pans 70-269

IV Luminaire Supports 70-269

V Grounding 70-270

VI Wiring of Luminaires 70-271

Vn Constmction of Luminaires 70-272

Vnilnstallation of Lampholders 70-273

IX Constmction of Lampholders :.70-273

X Lamps and Auxiliary Equipment 70-274

XI Special Provisions for Flush and Recessed Luminaires 70-274

Xn Constmction of Flush and Recessed Luminaires 70-274

Xm Special Provisions for Electric-Discharge Lighting Systems of 1000

Volts or Less 70-274

XTV Special Provisions for Electric-Discharge Lighting Systems of More

Than 1000 Volts 70-276

XV Lighting Track 70-277

XVI Decorative Lighting and Similar Accessories 70-277

41 1 Lighting Systems Operating at 30 Volts or Less 70-278

422 Appliances 70-278

IGeneral 70-278

n Installation 70-279

in Disconnecting Means 70-281

IV Constmction 70-282

VMaridng 70-283

424 Fixed Electric Space-Heating Equipment 70-284

IGeneral 70^84

n Installation 70-284

in Control and Protection of Fixed Electric Space-Heating

Equipment 70-284

IV Marking of Heating Equipment 70-286

V Electric Space-Heating Cables 70-286

VI Duct Heaters 70-288

vn Resistance-Type Boilers 70-289

Vin Electrode-Type Boilers 70-290

IX Electric Radiant Heating Panels and Heating Panel Sets 70-290

426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment 70-292

IGeneral 70-292

ninstaOation 70-293

ni Resistance Heating Elements 70-293

IV Impedance Heating 70-294

V Skin-Eflfect Heating 70-294

VI Control and Protection 70-295

427 Fixed Electric Heating Equipment for

Pipelines and Vessels 70-295

IGeneral 70-^95

n Installation 70-296

ni Resistance Heating Elements 70-296

IV Impedance Heating 70-297

V Induction Heating 70-297

VI Skin-Efifect Heating 70-298

vn Control and Protection 70-298

430 Motors, Motor Circuits, and Controllers 70-298

IGeneral 70-298

n Motor Circuit Conductors 70-304

in Motor and Branch-Circuit Overload Protection 70-306

IV Motor Branch-Circuit Short-Circuit and Ground-Fault Protection70-310

V Motor Feeder Short-Circuit and Ground-Fault Protection 70-3 13

Vt Motor Control Circuits 70-313

vn Motor Controllers 70-315

Vm Motor Control Centers 70-316

IX Disconnecting Means 70-3 17

X Adjustable — Speed Drive Systems 70-320

XI Over 600 Volts, Nominal 70-32 1

Xn Protection of Live Parts — All Voltages 70-322

xm Grounding — All Voltages 70-323

XIVTables 70-324

2010 California Electrical Code

70-xi

CONTENTS

ARTICLE

440 Air-Conditioning and Refrigerating Equipment 70-327

I General 70-327

n Disconnecting Means 70-329

in Branch-Circuit Short-Circuit and

Ground-Fault Protection 70-330

IV Branch-Circuit Conductors 70-331

V Controllers for Motor-Compressors 70-331

VI Motor-Compressor and Branch-Ciicuit

Overload Protection 70-332

Vn Provisions for Room Air Conditioners 70-333

445 Generators 70-334

450 Transformers and TransfomiCT Vaults (Including Secondary Ties) 70-335

I General Provisions 70-335

n Specific Provisions Applicable to

Different Types of Transfonners 70-339

m Transformer Vaults 70-341

455 Phase Converters 70-342

I General 70-342

n specific Provisions Applicable to

Different Types of Phase Converters 70-343

460 C^acitors 70-344

1 600 Volts, Nominal, and Under 70-344

n Over 600 Volts, Nominal 70-344

470 Resistors and Reactors 70-345

1 600 Volts, Nominal, and Under 70-345

n Over 600 Volts, Nominal 70-346

480 Storage Batteries 70-346

490 Equipment, Over 600 Volts, Nominal 70-347

IGeneral , 70-347

n Equipment — Specific Provisions 70-347

in Equipment — Metal-Enclosed Power Switchgear and
Industrial Control Assemblies 70-350

IV Mobile and Portable Equipment 70-352

V Electrode-Type Boilers 70-352

Chapter 5 Special Occupancies

500 Hazardoiis (Classified) Locations, Classes

I, n, and ffl, Divisions 1 and2 70-354

501 Class I Locations 70-362

IGeneral 70-362

n Wiring 70-363

mEquipment 70-368

502 Class n Locations 70-372

IGeneral ...70-^72

n Wiring 70^72

mEquipment 70-374

503 Class m Locations 70-378

IGeneral 70-378

n Wiring ; 70-378

mEquipment 70-379

504 Intrinsically Safe Systems 70-380

505 Class I, ZoneO,l, and 2 Locations 70-384

506 Zone 20,21,22 Locations forCombustibleDustsP^S

^^^ Z 70-398

510 Hazardous (Classified) Locations — Specific 70-404

511 Commercial Garages, Repair and Storage 70-404

513 Aircraft Hangars 70-407

ARTICLE

514 Motor Fuel Dispensing Facilities : 70-410

515 Bulk Storage Plants 70-414

516 Spray Application, Dipping, and Coating Processes 70-419

517 Health Care Facilities 70-425

IGeneral 70-425

n Wiring and Protection 70-427

m Essential Electrical System 70-430

IV Inhalation Anesthetizing Locations 70-437

V X-Ray Installations 70-440

VI Communications, Signaling Systems, Data Systems,
Fire Alarm Systems, and Systems Less Than 120 Volts,

Nominal 70-441

vn Isolated Power Systems 70-442

518 Assembly Occupancies 70-443

520 Iheaters, Audiaice Areas of Motion Picture and Television Studios,
Perfomiance Areas, and Similar Locations 70-444

IGeneral 70-444

n Fixed Stage Switchboanls 70-446

m Fixed Stage Equipment Other Than Switchboards 70-447

IV Portable Switchboaixls on Stage 70-448

V Portable Stage Equipment Other Than Switchboairis 70-451

VI Dressing Rooms 70-452

vn Grounding 70-453

iiPgloS^Sa^i 70^53

I. General 70453

n. Control Circuits 70453

m. Control Circuit Wiring Methods 70454

525 Carnivals, Circuses, Fairs, and Similar Events 70-455

I General Requirements 70-455

n Power Sources 70-455

m Wiring Methods 70-456

IV Grounding and Bonding 70-457

530 Motion Picture and Television Studios

and Similar Locations 70-457

IGeneral 70-457

n Stage or Set 70-458

m Dressing Rooms 70-460

IV Viewing, Cutting, and Patching Tables 70-460

V Cellulose Nitrate Film Storage Vaults 70-460

VI Substations 70-460

540 Motion Picture Projection Rooms 70-461

IGeneral 70-461

n Equipment and Projectors of the Professional Type 70-461

m Nonprofessional Projectors 70-462

rv Au(io Signal Processing, Amplification,

and Rqjroduction Equipment 70-462

545 Manufectured Buildings 70-462

547 Agricultural Buildings 70-463

550 Mobile Homes, Manufectured Homes, and Mobile Home Parks ... 70-466

IGeneral 70-466

n Mobile and Manufectured Homes 70-467

m Services and Feeders 70-474

551 Recreational Vehicles and Recreational Vehicle Pari<s 70-475

IGeneral : 70-475

n Combination Electrical Systems 70-477

ffl Other Power Sources 7CM77

IV Nominal 120-Volt or 120/240-Volt Systems 70-478

V Factory Tests 70-485

VI Recreational Vehicle Paries 70-485

70-xii

2010 California Electrical Code

CONTENTS

ARTICLE

■ 552 Paik Trailers 70-488

I General 70-488

n Low-Voltage Systems 70-488

m Combination Electrical Systems 70-489

IV Nominal 120-Volt or 120/240-Volt Systems 70-490

V Factory Tests 70-496

553 Floating Buildings 70-497

IGeneral ..70^97

n Services and Feeders 70-497

niGroxinding ...70497

555 Marinas and Boatyards 70-498

590 Temporary Installations 70-501

Chapter 6 Special Equipment

600 Electric Signs and Outline Lighting 70-504

IGeneral 70-504

n Field-Installed Skeleton Tubing aiid Wirmg 70-508

604 Manufactured Wiring Systems ....70-509

605 Office Fiffnishings (Consisting of Lighting

Accessories and Wired Partitions) 70-510

610 Cranes and Hoists 70-511

IGeneral 70-511

n Wiring : 70-512

m Contact Conductors 70-514

rv Disconnecting Means 70-515

V Overcmrent Protection 70-515

VI Control 70-516

Vn Grounding 70-516

620 Elevators, Dumbwaiters, Escalators,
Moving Walks, Wheelchair Lifts, and
Stairway Chair Lifts !..70-517

IGeneral 70-517

n Conductors 70-519

m Wiring 70-520

IV Installation of Conductors 7(^-523

V Traveling Cables 70-523

VI Disconnecting Means and Control 70-524

vn Overcurrent Protection 70-526

Vni Machine Rooms, Control Rooms,

Machinery Spaces, and Control Spaces 70-526

IX Grounding 70-527

X Emergency and Standby Power Systems 70-527

625 Electric Vehicle Charging System ....70-527

IGeneral 70-527

n Wiring Methods 70-528

in Equipment Constmction 70-528

IV Control and Protection 70-529

V Electric Vehicle Supply Equipment Locations 70-529

6^d-Efotr|iiedTii;ick>aiteg Spaces 70-531

IGeneral '.1 70-531

n. Electrified Truck Paridng Spaces Electrical Wiring Systems 70-532

m. Electrified Tmck Parking Space Supply 70-533

IV. Transport Refiigerated Unites (TRUs) 70-535

ARTICLE

630 Electric Welders 70-536

IGeneral '. 70-536

n Arc Welders 70-536

m Resistance Welders 70-537

P/ Welding Cable 70-538

640 Audio Signal Processing, Amplification,

and Reproduction Equipment 70-538

IGeneral 70-538

n Permanent Audio System Installations 70-542

ni Portable and Temporary Audio System Installations 70-542

645 Information Technology Equipment 70-544

647 Sensitive Electronic Equipment 70-546

650 Pipe Organs 70-547

660 X-P^y Equipment 70-548

IGeneral 70-548

n Control 70-549'

HI Transformers and Capacitors 70-549

IV Guarding and Grounding 70-549

665 Induction and Dielectric Heating Equipment 70-550

IGeneral. 70-550

n Guarding, Grounding, and Labeling 70-551

668 Electrolytic CeUs 70-551

669 Electroplating 70-554

670 Industrial Machinery ; 70-555

675 Electrically Driven or Controlled Irrigation Machines 70-556

IGeneral 70-556

n Center Pivot Irrigation Machines 70-558

680 Swimming Pools, Fountains, and Similar Installations 70-558

IGeneral 70-558

n Pennanently Installed Pools 70-561

niStorable Pools 70-568

IV Spas and Hot Tubs 70-568

VFountains 70-570

VI Pools and Tubs for Therapeutic Use.. 70-572

vn Hydromassage Bathtubs 70-572

682 Natural and Artifically Made Bodies of Water 70-573

IGeneral 70-^73

n Installation 70-573

in Grounding and Bonding 70-574

685 Integrated Electrical Systems 70-575

IGeneral : 70-575

n Orderly Shutdown ;.. 70-575

690 Solar Photovoltaic Systems 70-575

IGeneral 70-575

n Circuit Requirements 70-578

EI Disconnecting Means 70-580

IV Wiring Methods 70-581

V Grounding 70-583

VIMaridng..' 70-585

vn Connection to Other Sources 70-585

Vni Storage Batteries 70-587

DC Systems Over 600 Volts 70-588

2010 California Electrical Code

70-xiii

CONTENTS

ARTICLE

692 Fuel CeU Systems 70-588

I General 70-588

n Circuit Requirements 70-589

in Disconnecting Means 70-589

IV Wiring Methods 70-590

V Grounding 70-590

VI Marking 70-590

Vn Connection to Other Circuits 70-590

Vm Outputs Over 600 Volts 70-591

695 Fire Pumps 7(^591

Chapter 7 Special Conditions

700 Emergency Systems 70-596

I General 70-596

n Circuit Wiring 70-597

m Sources of Power 70-598

IV Emergency System Circuits for Lighting and Power 70-600

V Control — Emergency Lighting Circuits 70-600

VI Overcmrmt Protection 70-600

701 LegaUy Required Standby Systems 70-601

I General 70-601

n Circuit Wiring 70-602

m Sources of Power 70-602

IV Overcurrent Protection 70-603

702 Optional Standby Systems 70-604

I General 70-604

n Circuit Wiring 70-605

in Grounding 70-605

IV Sources of Power 70- 605

705 Interconnected Electric Power Production Sources 70-605

I. General 70-605

n. Utility-Interactive Inverters 70-608

m. Generators 70-609

7C^:CBiM'C^M€«b$'Fd^#'S^siwi:fCC^ 70-609

L General 70-609

n. Circuit Wiring and Equipment 70-610

in. Ppower Sources and Connection 70-612

IV. Overcurrent Protection 70-613

V. System Performance and Analysis 70-614

720 Circuits and Equipment Operating at Less ,

Than 50 Volts 70-614

725 Class 1 , Class 2, and Class 3

Remote-Control, Signaling, and Power-Limited Circuits 70-614

I General 70-614

n Class 1 Circuits 70-615

ffl Class 2 and Class 3 Circuits 70-^17

IV Listing Requirements 70-622

727 Instrumentation Tray Cable: Type rrC 70-624

760 Fire Alami Systems 70-625

I General '. 70-625

n Non-Power-Limited Fire Alami (NPLFA) Circuits 70-626

m Power-Limited Fire Alami (PLFA) Circuits 70-628

IV Listing Requirements ...70-631

770 Optical Fiber Cables and Raceways 70-633

I General 70-633

HCabl^CXitsae^idEi^OTigBi;#3^ 70-634

Ifl Protection .'....'...7..;.....'.........' 70-635

IV"aHiii®ig]S^^Q^ 70-635

VteaIM<mS»odsWt8MBilib^ 70-636

yiLisiirigRequiremmts 70-638

Chapter 8 Communications Systems

800 Communications Circuits 70-640

I General 70-640

n Wires and Cables Outside and Entering Buildings 70-641

m Protection 70-642

IV Grounding Methods 70-644

V M^M^Msjl^^ Wires and Cables Within Buildings 70-645

VI Listing Requirements 70-647

ARTICLE

810 Radio and Television Equipment 70-649-

IGeneral 70-649

n Receiving Equipment — Antenna Systems 70-650

in Amateur Transmitting and Receiving

Stations — Antenna Systems 70-652

IV Interior Installation — Transmitting Stations 70-653

820 Community Antenna Television and Radio

Distribution Systems 70-653

IGeneral : 70-653

n|MB Cables Outside and Entering Buildings 70-654

m Protection 70-655

IV.Grounding Methods 70-656

V gHHSlSifiSti Within Buildings 70-657

VI Listing Requirements 70-559

830 Networic-Powered Broadband Communications Systems 70-660

IGeneral 70-660

n Cables Outside and Entering Buildings 70-662

mProtection 70-664

IV Grounding Methods 70-666

V fosfciiiado^ Methods Within Buildings 70-667

VI Listing Requirements 70-669

TABLES

Chapter 9 Tables

1 Percent of Cross Section of Conduit and

Tubing for Conductors 70-671

2 Radius ofConduit and Tubing Bends 70-671

4 Dimensions and Percent Area ofConduit

and Tubing (Areas ofConduit or Tubing
for the Combinations of Wires Permitted
inTablel, Chapter 9) 7C^-672

5 Dimensions of Insulated Conductors and

Fixture Wir^s 70-676

5ACompact^^HAluminumBuildingWire

Nominal Dimensions and Areas 70-680

8 Conductor Properties 70-681

9 Alternating-Current Resistance and

Reactance for 600-Volt Cables, 3-Phase,
60 Hz, 75°C (167°F) — Three Single
Conductors in Conduit 70-682

1 1(A) Class 2 and Class 3 Alternating-Current

Power Source Limitations 70-684

1 1 (B) Class 2 and Class 3 Direct-Current Power

Source Limitations 70-684

12(A) PLFA Alternating-Current Power Source Limitations 70-685

12(B) PLFA Direct-Current Power Source Limitations 70-685

Annex A 70-686

AnnexB 70-689

Annexe 70-^03

Annex D 70-^63

AnnexE 70-^73

Annex F 70-774

AnnexG 70-776

AnnexH 70-778

Index 70-785

70-xiv

2010 California Electrical Code

CALIFORNIA MATRIX ADOPTION TABLES

California Matrix Adoption Tables

Format of the Matrix Adoption Tables

The matrix adoption tables, which follow, show the user which state agencies have
adopted and/or amended given sections of model code for applications within their
respective authorities. See Article 89, Sections 089.102 through 89.114, for building
application and enforcement responsibilities.

The side headings identify the scope of the state agencies' adoption as follows:

Adopt the entire NEC article without state amendments

If there is an "X" under a particular state agency's acronym in this row, it means that
particular state agency has adopted the entire model code chapter without any state
amendments.

Example:

ARTICLE 89 - GENERAL CODE PROVISIONS

Adopting Agency

BSC

SFM

HCD

DSA

AC SS

OSHPD

DPH
AC

Adopt Entire Article

Adopt Entire Article as amended
(amended sections listed below)

Adopt only those sections that are
listed below

Article / Section

:£Z.^

89.101

89.102

Adopt the entire NEC article as amended (amendments listed below)

If there is an "X" under a particular state agency's acronym in this row, it means that
particular state agency has adopted the entire model code chapter, with state amendments.

Each state-amended section that the agency has added to that particular chapter is
listed. There will be an "X" in the column, by that particular section, under the agency's
acronym, as well as an "X" by each section that the agency has adopted.

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.

2010 California Electrical Code

70-xv

CALIFORNIA MATRIX ADOPTION TABLES

Example:

ARTICLE 89 - GENERAL CODE PROVISIONS

Adopting Agency

BSC

SFM

HCD

DSA

OSHPD

DPH

Adopt Entire Article

Adopt Entire Article as amended
(amended sections listed below)

/■■ {■■■'■'-■

:' ■ .r
;■' ' -A

Adopt only those sections that are listed
below

%..

1 J IP

,3 , '''

Article / Section

89.101

89.102

Example:

Adopt only those sections which are listed below:

If there is an "X" under a particular state agency's acronym in this row, it means that
particular state agency is adoption only specific model code or state-amended sections
within this chapter. There will be an "X" in the column under the agency's acronym, as
well as an "X" by each section that the agency has adopted.

ARTICLE 89 - GENERAL CODE PROVISIONS

Adopting Agency

BSC

SFM

HCD

DSA

OSHPD

DPH

Adopt Entire Article

Adopt Entire Article as amended
(amended sections listed below)

Adopt only those sections that are listed
below

m\ : i

'P\

,;,!

■ ,,■

Article / Section

" ■

' ". ''

89.101

89.102

Legend of Abbreviations of Adopting State Agencies

BSC California Building Standards Commission

SFM Office of the State Fire Marshal

HCD Department of Housing and Community Development

DSA-AC Division of the State Architect - Access Compliance

DSA-SS Division of the State Architect - Structural Safety

DSA-SS/CC Division of the State Architect - Structural Safety/Community Colleges

OSHPD Office of Statewide Health Planning and Development

DPH California Department of Public Health

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.
'^^■^^^ 2010 California Electrical Code

ARTICLE 89 CALIFORNIA MATRIX ADOPTION TABLE

ARTICLE 89 - GENERAL CODE PROVISIONS

Adopting Agency

BSC

SFM

HCD

DSA

OSHPD

DPH

1-AC

SS/CC

Adopt Entire Article

Adopt Entire Article as amended
(amended sections listed below)

Adopt only those articles / sections tliat
are listed below

Article / Section

89.101

89.102

89.107

89.108

89.109.1

89.109.2.1

89.109.2.2

89.110.1

89.110.2

89.110.3

89.110.4

89.111

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is apphcable to structures subject to HCD 1 and/or HCD 2.
2010 California Electrical Code

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.

2010 California Electrical Code

CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

CALIFORNIA ARTICLE 89
GENERAL CODE PROVISIONS

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SECTION 89.101
GENERAL

89.101.1 Title. These regulations shall be known as the
California Electrical Code, may be cited as such and will be
referred to herein as ''this code. " The California Electrical
Code is Part 3 of twelve parts of the official compilation and
publication of the adoption, amendment, and repeal of
electrical regulations to the California Code of Regulations,
Title 24, also referred to as the California Building Standards
Code. This part incorporates by adoption the 2008 National
Electrical Code of the National Fire Protection Association
with necessary California amendments.

89.101.2 Purpose. The purpose of this code is to establish the
minimum requirements to safeguard the public health, safety
and general welfare through structural strength, means of
egress facilities, stability, access to persons with disabilities,
sanitation, adequate lighting and ventilation, and energy
conservation; safety to life and property from fire and other
hazards attributed to the built environment; and to provide
safety to fire fighters and emergency responders during
emergency operations.

89.1013 Scope. The provisions of this code shall apply to the
construction, alteration, movement, enlargement, replacement,
repair, equipment, use and occupancy, location, maintenance,
removal and demolition of every building or structure or any
appurtenances connected or attached to such building or
structures throughout the State of California.

89.101.3.1 Nonstate-Regulated Buildings, Structures^
and Applications. Except as modified by local ordinance
pursuant to Section 89.101.8, the building standards in
the California Code of Regulations, Title 24, Parts 2, 2.5,
3, 4, 5, 6,9, 10 and 11 shall apply to all occupancies and
applications not regulated by a state agency.

89.101.3.2 State-Regulated Buildings, Structures, and
Applications, The model code, state amendments to the
model code, and/or state amendments where there are no
relevant model code provisions shall apply to the
following buildings, structures, and applications
regulated by state agencies as referenced in the Matrix
Adoption Tables and as specified in Sections 89.102
through 89.114, except where modified by local
ordinance pursuant to Section 89.101.8. When adopted
by a state agency, the provisions of this code shall be
enforced by the appropriate enforcing agency, but only to
the extent of authority granted to such agency by the state
legislature.

Note: See Preface to distinguish the model code
provisions from the California provisions.

1. State-owned buildings, including buildings
constructed by the Trustees of the California State
University, and to the extent permitted by California
laws, buildings designed and constructed by the
Regents of the University of California, and regulated
by the Building Standards Commission. See Section
89.102 for additional scope provisions.

2. Reserved for Corrections Standards Authority. See
Section 89.103 for additional scope provisions.

3. Reserved for the Department of Consumer Affairs.
See Section 89.104 for additional scope provisions.

4. Reserved for the California Energy Commission.
See Section 89.105 for additional scope provisions.

5. Reserved for the Department of Food and Agriculture.
See Section 89.106 for additional scope provisions.

6. Organized camps, laboratory animal quarters, public
swimming pools, radiation protection, commissaries setving
mobile food preparation vehicles and wild animal
quarantine facilities regulated by the California Department
of Public Health (DPH). See Section 89.107 for additional
scope provisions.

7. Hotels, motels, lodging houses, apartment houses,
dwellings, dormitories, condominiums, shelters for
homeless persons, congregate residences, employee
housing, factory-built housing, and other types of dwellings
containing sleeping accommodations with or without
common toilets or cooking facilities. See Section
89. 108.2.1.1 for additional scope provisions,

8. Accommodations for persons with disabilities in
buildings containing newly constructed covered
multifamily dwellings, new common use spaces serving
existing covered multifamily dwellings, additions to
existing buildings where the addition alone meets the
definition of ''COVERED MULTIFAMILY
DWELLINGS,*' and common-use spaces serving
covered multifamily dwellings which are regulated by
the Department of Housing and Community
Development. See Section 89.108.2.1.2 for additional
scope provisions.

9. Permanent buildings and permanent accessory
buildings or structures constructed within mobilehome
parks and special occupancy parks regulated by the
Department of Housing and Community Development See
Section 89. 1 08. 2. 1 . 3 for additional scope provisions.

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2010 California Electrical Code

70-1

CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

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10. Accommodations for persons with disabilities
regulated by the Division of the State Architect. See
Section 89. 1 09. 1 for additional scope provisions.

11. Public elementary and secondary schools,
community college buildings, and state-owned or state-
leased essential service buildings regulated by the
Division of the State Architect. See Section 89.109.2 for
additional scope provisions.

12. Qualified historical buildings and structures and
their associated sites regulated by the State Historical
Building Safety Board with the Division of the State
Architect. See Section 89.109.3 for additional scope
provisions.

13. General acute care hospitals, acute psychiatric
hospitals, skilled nursing and/or intermediate care
facilities, clinics licensed by the California Department
of Public Health (DPH) and correctional treatment
centers regulated by the Office of Statewide Health
Planning and Development. See Section 89.110 for
additional scope provisions.

14. Applications regulated by the Office of the State
Fire Marshal include, but are not limited to, the
following in accordance with Section 89.111:

1. Buildings or structures used or intended for use as an:

1.1. Asylum, jail.

1.2. Mental hospital, hospital, home for the elderly,
children's nursery, children's home or institution,
school or any similar occupancy of any capacity.

1.3. Theater, dancehall, skating rink, auditorium,
assembly hall, meeting hall, nightclub, fair building, or
similar place of assemblage where 50 or more persons
may gather together in a building, room or structure
for the purpose of amusement, entertainment,
instruction, deliberation, worship, drinking or dining,
awaiting transportation, or education.

1.4. Small family day care homes, large family day
care homes, residential facilities and residential
facilities for the elderly and residential care facilities.

1.5. State institutions or other state-owned or state-
occupied buildings.

1.6. High rise structures.

1. 7. Motion picture production studios.

1.8. Organized camps.

1.9. Residential structures.

2. Tents, awnings or other fabric enclosures used in
connection with any occupancy.

3. Fire alarm devices, equipment and systems in
connection with any occupancy.

4. Hazardous materials, flammable and
combustible liquids.

5. Public school automatic fire detection, alarm, and
sprinkler systems.

6. Wildland-Urban Interface (WUI)fire areas.

15. Reserved for the State Librarian. See Section 89,1 12 for
additional scope provisions.

16. Reserved for the Department of Water Resources. See
Section 89.1 13 for additional scope provisions.

17. Reserved for the California State Lands Commission.
See Section 89.1 14 for additional scope provisions.

89.101,3,3 Exempted from this Code. This code does
not cover:

(A) 1. Installations in ships, watercraft other than
floating dwelling units, railway rolling stock,
aircraft, automotive vehicles, commercial coaches,
mobilehomes, and recreational vehicles.

(B) 2. Installations underground in mines, mine
shafts and tunnels.

(C) 3. Installations of railways for generation,
transformation, transmission, or distribution of
power used exclusively for operation of rolling stock
or installations used exclusively for signaling and
communication purposes.

(D) 4. Installation of communication equipment
under the exclusive control of communication
utilities, located outdoors or in building spaces used
exclusively for such installations.

(E) 5. Installations under the exclusive control of
electrical utilities for the purpose of communication,
or metering; or for the generation, control,
transformation, transmission, and distribution of
electrical energy located in buildings used
exclusively by utilities for such purposes or located
outdoors on property owned or leased by the utility
or on public highways, streets, roads, etc., or
outdoors by established rights on private property.

Exception to (D)4 and (E)5: In places of
employment, the following shall apply: installations
of conductors, equipment and associated enclosures
subject to the jurisdiction of the California Public
Utilities Commission, that are owned, operated and
maintained by an electric, communications or
electric railway utility, but not including conduit,
vaults, and other like enclosures containing
conductors and equipment of such a utility when
located indoors or on premises not used exclusively
for utility purposes, but do not apply to the utility 's
conductors and equipment therein.

(F) 6. Installations on highways or bridges.

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70-2

2010 California Electrical Code

CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

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89.101.4 Annexes, Provisions contained in the annexes of
this code shall not apply unless specifically adopted by a
state agency or adopted by a local enforcing agency in
compliance with Health and Safety Code Section 18901 et
seq. for Building Standards Law, Health and Safety Code
Section 17950 for State Housing Law and Health and
Safety Code Section 13 869. 7 for Fire Protection Districts,
See Section 89 J 01. 8 of this code.

89.101.5 Referenced Codes, The codes, standards and
publications adopted and set forth in this code, including
other codes, standards and publications referred to therein
are, by title and date of publication, hereby adopted as
standard reference documents of this code. When this code
does not specifically cover any subject related to building
design and construction, recognized architectural or
engineering practices shall be employed. The National Fire
Codes, standards and the Fire Protection Handbook of the
National Fire Protection Association are permitted to be
used as authoritative guides in determining recognized fire
prevention engineering practices.

89.101.6 Non-Building Standards, Orders and
Regulations. Requirements contained in the National
Electrical Code, or in any other referenced standard, code
or document, which are not building standards as defined
in Health and Safety Code Section 18909 shall not be
construed as part of the provisions of this code. For
nonbuilding standards, orders, and regulations, see other
titles of the California Code of Regulations.

89.101. 7 Order of Precedence and Use.

89.101.7.1 Differences. In the event of any differences
between these building standards and the standard
reference documents, the text of these building standards
shall govern.

89.101.7.2 Specific Provisions, Where a specific
provision varies from a general provision, the specific
provision shall apply,

89.10L7.3 Conflicts, When the requirements of this code
conflict with the requirements of any other part of the
California Building Standards Code, Title 24, the most
restrictive requirements shall prevail.

89.101.8 City, County, or City and County Amendments,
Additions or Deletions. The provisions of this code do not
limit the authority of city, county, or city and county
governments to establish more restrictive and reasonably
necessary differences to the provisions contained in this
code pursuant to complying with Section 89.101.8.1. The
effective date of amendments, additions, or deletions to
this code by city, county or city and county filed pursuant
to Section 89.101.8.1 shall be the date filed. However, in
no case shall the amendments, additions or deletions to
this code be effective any sooner than the effective date of
this code.

Local modifications shall comply with Health and Safety
Code Section 18941,5 for Building Standards Law, Health
and Safety Code Section 1 7958 for State Housing Law or
Health and Safety Code Section 13869.7 for Fire
Protection Districts.

89,101.8.1 Findings and Filings.

1. The city, county, or city and county shall make
express findings for each amendment, addition or
deletion based upon climatic, topographical, or
geological conditions.

Exception: Hazardous building ordinances and
programs mitigating unreinforced masonry buildings.

2. The city, county, or city and county shall file the
amendments, additions, or deletions expressly

marked and identified as to the applicable findings.
Cities, counties, cities and counties, and fire

departments shall file the amendments, additions or
deletions, and the findings with the California

Building Standards Commission at 2525 Natomas
Park Drive, Suite 130, Sacramento, CA 95833,

3. Findings prepared by fire protection districts
shall be ratified by the local city, county, or city and
county and filed with the California Department of
Housing and Community Development, Division of
Codes and Standards, P.O. Box 1407, Sacramento, CA
95812-1407 or at 1800 3rd Street, Room 260,
Sacramento, CA 95811.

89.101.9 Effecdve Date of this Code. Only those standards
approved by the California Building Standards Commission
that are effective at the time an application for building permit
is submitted shall apply to the plans and specifications for, and
to the construction performed under, that permit For the
effective dates of the provisions contained in this code, see the
History Note page of this code.

89.101.10 Availability of Codes. At least one complete
copy each of Titles 8, 19, 20, 24, and 25 with all revisions
shall be maintained in the office of the building official
responsible for the administration and enforcement of this
code. Each state department concerned and each city,
county or city and county shall have an up-to-date copy of
the code available for public inspection. See Health and
Safety Code Section 18942 (d) (1) and (2).

89.101.11 Format This part fundamentally adopts the
National Electrical Code by reference on a chapter-by-
chapter basis. Such adoption is reflected in the Matrix
Adoption Table of each chapter of this part. When the Matrix
Adoption Tables make no reference to a specific chapter of the
National Electrical Code, such chapter of the National
Electrical Code is not adopted as a portion of this code.

89.101.12 Validity, If any chapter, article, section,
subsection, sentence, clause or phrase of this code is for
any reason held to be unconstitutional, contrary to statute,

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2010 California Electrical Code

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CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

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exceeding the authority of the state as stipulated by
statutes, or otherwise inoperative, such decision shall not
affect the validity of the remaining portion of this code.

SECTION 89.102

BUILDING STANDARDS COMMISSION

89,102,1 Specific scope of application of the agency
responsible for enforcement, the enforcement agency, and
the specific authority to adopt and enforce such
provisions of this code, unless otherwise stated.

L State Buildings for all occupancies.

Application - State buildings (all occupancies), including
buildings constructed by the Trustees of the California
State University and the Regents of the University of
California where no state agency has the authority to adopt
building standards applicable to such buildings.

Enforcing Agency ~ State or local agency specified by
the applicable provisions of law.

Authority Cited - Health and Safety Code section
18934.5.

Reference ~ Health and Safety Code, Division 13, Part
2,5, commencing with section 18901.

2, University of Californiay California State Universities,
and California Community Colleges,

Application - Standards for lighting for parking lots
and primary campus walkways at the University of
California, California State Universities, and
California Community Colleges,

Enforcing Agency - State or local agency specified by
the applicable provisions of law.

Authority Cited- Government Code section 14617.

Reference - Government Code section 1461 7,

3, Existing State-Owned Buildings, including those owned
by the University of California and by the Calif omia State
University- Building seismic retrofit standards including
abating falling hazards of structural and nonstructural
components and strengthening of building structures. See
also Division of the State Architect

Enforcing Agency - State or local agency specified by
the applicable provisions of law.

Authority Cited- Government Code section 16600

Reference - Government Code sections 16600
through 16604

4, Unreinforced Masonry Bearing Wall Buildings,

Application - Minimum seismic strengthening standards
for buildings specified in Appendix Chapter 1 of the
California Code for Building Conservation, except for
buildings subject to building standards adopted pursuant
to Part 1.5 (commencing with Section 17910).

Enforcing Agency - State or local agency specified by
the applicable provisions of law.

Authority Cited - Health and Safety Code section
18934.6

Reference - Health and Safety Code sections 18901
through 18949

89.102.2 Alternative Materials, Design And Methods Of
Construction And Equipment.

The provisions of this code are not intended to prevent the
installation of any material or to prohibit any design or
method of construction not specifically prescribed by this
code, provided that any such alternative has been approved.
An alternative material, design or method of construction shall
be approved where the building official finds that the proposed
design is satisfactory and complies with the intent of the
provisions of this code, and that the material, method or work
offered is, for the purpose intended, at least the equivalent of
that prescribed in this code in quality, strength, effectiveness,
fire resistance, durability and safety.

89.102.2.1 Research Reports. Supporting data, where
necessary to assist in the approval of materials or
assemblies not specifically provided for in this code, shall
consist of valid research reports from approved sources.

89.102.2.2 Tests. Whenever there is insufficient evidence
of compliance with the provisions of this code, or
evidence that a material or method does not conform to
the requirements of this code, or in order to substantiate
claims for alternative materials or methods, the building
official shall have the authority to require tests as
evidence of compliance to be made at no expense to the
jurisdiction. Test methods shall be as specified in this
code or by other recognized test standards. In the
absence of recognized and accepted test methods, the
building official shall approve the testing procedures.
Tests shall be performed by an approved agency. Reports
of such tests shall be retained by the building official for
the period required for retention of public records,

SECTION 89.103

RESERVED FOR CORRECTIONS STANDARDS
AUTHORITY

SECTION 89.104

RESER VED FOR THE DEPARTMENT OF
CONSUMER AFFAIRS

SECTION 89.105

RESERVED FOR THE CALIFORNIA ENERGY
COMMISSION

SECTION 89.106

RESERVED FOR THE DEPARTMENT OF FOOD
AND A GRIGUL TURE

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SECTION 89.107

CALIFORNIA DEPARTMENT OF PUBLIC
HEALTH

89,107 Specific scope of application of the agency
responsible for enforcement, the enforcement agency, and
the specific authority to adopt and enforce such
provisions of this code, unless otherwise stated.

Application -Commissaries serving mobile food
preparation units and public swimming pools

Enforcing Agency - The California Department of
Public Health and the local health agency.

Authority Cited ~~ Health and Safety Code sections ,
114304, 116050, and 131200.

Reference - Health and Safety Code sections
114304, 116050, 116053 and 131200.

SECTION 89,108

DEPARTMENT OF HOUSING AND COMMUNITY
DEVELOPMENT

89.108.1 Purpose, The purpose of this code is to
establish minimum standards to protect the health,
safety, and general welfare of the occupant and the
public against hazards that may arise from the use of
electricity by governing the design, construction,
reconstruction, installation, quality of materials,
location, operation, and maintenance or use of
electrical equipment, wiring and systems.

89.108.2 AUTHORITY AND ABBREVIATIONS

89,108,2,1 General, The Department of Housing
and Community Development is authorized by law
to promulgate and adopt building standards and
regulations for several types of building
applications. These applications are grouped and
identified by abbreviation in the Matrix Adoption
Tables to show which model code sections and
amendments are applicable to each application.
The applications under the authority of the
Department of Housing and Community
Development are listed in Sections 89,108.2.1.1
through 89. 108.2. L3.

89,108,2,1,1 Housing Construction, Application -
Hotels, motels, lodging houses, apartment houses,
dwellings, dormitories, condominiums, shelters for
homeless persons, congregate residences, employee
housing, factory-built housing and other types of
dwellings containing sleeping accommodations with or
without common toilet or cooking facilities including
accessory buildings, facilities, and uses thereto.
Sections of this code which pertain to applications
listed in this section are identified in the Matrix
Adoption Table using the abbreviation 'HCD 1 ".

Enforcing Agency-Local building department
or the Department of Housing and Community
Development.

Authority Cited: Health and Safety Code
Sections 17040, 17050, 17920.9, 17921,
1 7921. 3, 17921.6, 17921.10, 17922, 17922.6,
17922.12, 17927, 17928, 17959.6, 18300, 18552,
18554, 18620, 18630, 18640, 18670, 18690,
18691, 18865, 18871.3, 18871.4, 18873,
18873.1, 18873.2, 18873.3, 18873.4, 18873.5,
18938.3, 18944.11, and 19990; and Government
Code Section 12955.1.

Reference: Health and Safety Code Sections
17000 through 17062.5, 17910 through 17995.5,
18200 through 18700, 18860 through 18874, and
19960 through 19997; and Government Code
Sections 12955.1 and 12955.1.1.

89,108,2,1,2 Housing Accessibility, Application-
Covered multifamily dwellings as defined in
Chapter llA of the California Code of
Regulations, Title 24, Fart 2, also known as the
California Building Code (CBC) including, but not
limited to, lodging houses, dormitories,
timeshares, condominiums, shelters for homeless
persons, congregate residences, apartment houses,
dwellings, employee housing, factory-built housing
and other types of dwellings containing sleeping
accommodations with or without common toilet or
cooking facilities.

Sections of this code identified in the Matrix
Adoption Table by the abbreviation 'HCD 1-
AC" require specific accommodations for
''PERSONS WITH PHYSICAL DISABILITIES, "
as defined in CBC Chapter 11 A. The
application of such provisions shall be in
conjunction with other requirements of this
code and apply only to newly-constructed
''COVERED MULTIFAMILY DWELLINGS" as
defined in CBC Chapter 11 A. 'HCD 1-AC"
applications include, but are not limited to, the
following:

(1) All newly constructed ''COVERED
MULTIFAMILY DWELLINGS'' as defined in CBC
Chapter 1 1 A.

(2) New "COMMON USE AREAS" as defined in
CBC Chapter llA serving existing covered
multifamily dwellings.

(3) Additions to existing buildings, where the
addition alone meets the definition of
"COVERED MULTIFAMILY DWELLINGS" as
defined in CBC Chapter 11 A.

(4) Common use areas serving covered
multifamily dwellings.

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(5) Where any portion of a building's exterior is
preserved, but the interior of the building is
removed, including all structural portions of
floors and ceilings, the building is considered a
new building for determining the application of
CBQ Chapter 11 A.

"HCD 1-AC" building standards generally do
not apply to public use areas or public
accommodations such as hotels and motels.
Public me areas, public accommodations and
housing which is publicly funded as defined in
Chapter 2 of the CBC are subject to the Division
of the State Architect (DSA-AC) and are
referenced in Section 109. L

Enforcing Agency-Local building department or
the Department of Housing and Community
Development.

Authority Cited: Health and Safety Code
Sections 17040, 17050, 17920.9, 17921,
17921.3, 17921.6, 17921.10, 17922, 17922.6,
17922.12, 17927, 17928, 17959.6, 18300, 18552,
18554, 18620, 18630, 18640, 18670, 18690,
18691, 18865, 18871.3, 18871.4, 18873,
18873.1, 18873.2, 18873.3, 18873.4, 18873.5,
18944.11, and 19990; and Government Code
Section 12955.1.

Reference: Health and Safety Code Sections
17000 through 17062.5, 17910 through 17995.5,
18200 through 18700, 18860 through 18874,
and 19960 through 19997; and Government
Code Sections 12955,1 and 12955.1.1.

89.108.2,1,3 Permanent Buildings in Mobilehome
Parks and Special Occupancy Parks. Application -
Permanent buildings, and permanent accessory
buildings or structures, constructed within mobilehome
parks and special occupancy parks that are under the
control and ownership of the park operator. Sections of
this code which pertain to applications listed in this
section are identified in the Matrix Adoption Table
using the abbreviation 'HCD 2 '\

Enforcing Agency — Local building department or
other local agency responsible for the enforcement of
Health and Safety Code, Division 13, Part 2.1,
commencing with Section 18200 for mobilehome
parks and Health and Safety Code, Division 13, Part
2.3, commencing with Section 18860 for special
occupancy parks; or the Department of Housing and
Community Development

18871.3, 18871.4, 18873, 18873.1, 18873.2,
18873.3, 18873.4, 18873.5, 18944.11, and 19990;
and Government Code Section 12955.1.

89.108,3 LOCAL ENFORCING AGENCY

89.108.3.1 Duties and Powers. The building
department of every city, county or city and county
shall enforce all the provisions of law, this code, and
the other rules and regulations promulgated by the
Department of Housing and Community Development
pertaining to the installation, erection, construction,
reconstruction, movement, enlargement, conversion,
alteration, repair, removal, demolition or
arrangement of apartment houses, hotels, motels,
lodging houses and dwellings, including accessory
buildings, facilities, and uses thereto.

The provisions regulating the erection and
construction of dwellings and appurtenant structures
shall not apply to existing structures as to which
construction is commenced or approved prior to the
effective date of these regulations. Requirements
relating to use, maintenance and occupancy shall
apply to all dwellings and appurtenant structures
approved for construction or constructed before or
after the effective date of this code.

For additional information regarding the use and
occupancy of existing buildings and appurtenant
structures, see California Code of Regulations, Title
25, Division 1, Chapter 1, Subchapter 1,
commencing with Article 1, Section 1.

89.108.3.2 Laws, Rules, and Regulations. Other than
the building standards contained in this code, and
notwithstanding other provisions of law, the statutory
authority and location of the laws, rules, and
regulations to be enforced by local enforcing agencies
are listed by statute in Sections 89.108.3.2.1 through
89.108.3.2.5 below:

89.108.3.2.1 State Housing Law. Refer to the State
Housing Law, California Health and Safety Code,
Division 13, Part 1.5, commencing with Section
17910 and California Code of Regulations, Title
25, Division 1, Chapter 1, Subchapter 1,
commencing with Section 1, for the erection,
construction, reconstruction, movement,

enlargement, conversion, alteration, repair,
removal, demolition or arrangement of apartment
houses, hotels, motels, lodging houses and
dwellings, including accessory buildings, facilities,
and uses thereto.

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89.108.3.2.2 Mobilehome Parks Act. Refer to
the Mobilehome Parks Act, California Health
and Safety Code, Division 13, Part 2.1,
commencing with Section 18200 and California
Code of Regulations, Title 25, Division 1,
Chapter 2, commencing with Section 1000 for
mobilehome park administrative and
enforcement authority, permits, plans, fees,
violations, inspections and penalties both within
and outside mobilehome parks .

Exception: Mobilehome parks where the
Department of Housing and Community
Development is the enforcing agency.

89.108.3.2.3 Special Occupancy Parks Act. Refer
to the Special Occupancy Parks Act, California
Health and Safety Code, Division 13, Part 2.3,
commencing with Section 18860 and California
Code of Regulations, Title 25, Division 1, Chapter
2.2, commencing with Section 2000 for special
occupancy park administrative and enforcement
authority, permits, fees, violations, inspections and
penalties both within and outside of special
occupancy parks.

Exception: Special occupancy parks where the
Department of Housing and Community
Development is the enforcing agency.

89.108.3.2.4 Employee Housing Act Refer to the
Employee Housing Act, California Health and
Safety Code, Division 13, Part 1, commencing with
Section 17000 and California Code of Regulations,
Title 25, Division 1, Chapter 1, Subchapter 3,
commencing with Section 600 for employee
housing administrative and enforcement authority,
permits, fees, violations, inspections and penalties.

89.108.3.2.5 Factory-Built Housing Law. Refer to
the Factory-Built Housing Law, California Health
and Safety Code, Division 13, Part 6, commencing
with Section 19960 and California Code of
Regulations, Title 25, Division 1, Chapter 3,
Subchapter 1, commencing with Section 3000 for
factory-built housing administrative and
enforcement authority, permits, fees, violations,
inspections and penalties.

89.108.4 PERMITS, FEES, APPLICATIONS AND
INSPECTIONS

89.108.4.1 Permits, (a) Except as exempted in
paragraph (b) of this subsection, a written construction
permit shall be obtained from the enforcing agency
prior to the erection, construction, reconstruction,
installation, movement, or alteration of any electrical
system.

(b) Consistent with the requirements of Section 1 7960 of
the Health and Safety Code, the local enforcing agency

shall enforce the requirements of this code, but shall
exempt the following activities from the requirement for
a permit or inspection.

1. Listed cord and plug connected temporary
decorative lighting.

2. Reinstallation of attachment plug receptacles, but
not the outlets therefore.

3. Repair or replacement of branch circuit
overcurrent devices of the required capacity in the
same location.

4. Installation or maintenance of communications
wiring, devices, appliances, apparatus or equipment

Exemptions from permit and inspection requirements
shall not be deemed to grant authorization for any work
to be done in any manner in violation of any other
provision of law or this code.

89.108.4.2 Fees. Subject to other provisions of law, the
governing body of any city, county or city and county
may prescribe fees to defray the cost of enforcement of
rules and regulations promulgated by the Department of
Housing and Community Development The amount of
the fees shall not exceed the amount reasonably
necessary to administer or process permits, certificates,
forms, or other documents, or to defray the costs of
enforcement For additional information, see State
Housing Law, Health and Safety Code, Division 13,
Part 1.5, Section 17951 and California Code of
Regulations, Title 25, Division 1, Chapter 1, Subchapter
1, Article 3, commencing with Section 6.

89.108.4.3 Plan Review and Time Limitations. Subject to
other provisions of law, provisions related to plan
checking, prohibition of excessive delays and contracting
with or employment of private parties to perform plan
checking are set forth in State Housing Law, Health and
Scfety Code Section 17960.1, and for employee housing,
in Health and Safety Code Section 17021.

89.108.4.3.1 Retention of Plans. The building
department of every city, county or city and county
shall maintain an official copy, microfilm, or
electronic or other type of photographic copy of the
plans of every building, during the life of the building,
for which the department issued a building permit

Exceptions:

1. Single or multiple dwellings not more than
two stories and basement in height.

2. Garages and other structures appurtenant to
buildings listed in Exception (1).

3. Farm or ranch buildings appurtenant to
buildings listed in Exception (1).

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4. Any one-story building where the span
between bearing walls does not exceed 25 feet
(7620 mm), except a steel frame or concrete
building.

All plans for common interest developments as
defined in Section 1351 of the California Civil
Code shall be retained. For additional
information regarding plan retention and
reproduction of plans by an enforcing agency,
see Health and Safety Code Sections 19850
through 19852.

89.108.4,4 Inspections. Construction or work for
which a permit is required shall be subject to
inspection by the building official and such
construction or work shall remain accessible and
exposed for inspection purposes until approved.
Approval as a result of an inspection shall not be
construed to be an approval of a violation of the
provisions of this code or other regulations of the
Department of Housing and Community
Development

89.108.5 RIGHT OF ENTRY FOR ENFORCEMENT

89.108.5.1 General. Subject to other provisions of
law, officers and agents of the enforcing agency may
enter and inspect public and private properties to
secure compliance with the rules and regulations
promulgated by the Department of Housing and
Community Development. For limitations and
additional information regarding enforcement, see
the following:

1. For applications subject to State Housing Law
as referenced in Section 89.108.3.2.1 of this code,
refer to Health and Safety Code, Division 13, Part
1.5, commencing with Section 17910 and
California Code of Regulations, Title 25, Division

1. Chapter 1, Subchapter 1, commencing with
Section 1.

2. For applications subject to the Mobilehome
Parks Act as referenced in Section 89,108.3.2.2 of
this code, refer to Health and Safety Code,
Division 13, Part 2.1, commencing with Section
18200 and California Code of Regulations, Title
25, Division 1, Chapter 2, commencing with
Section 1000.

3. For applications subject to the Special
Occupancy Parks Act as referenced in Section
89.108.3.2.3 of this code, refer to Health and
Safety Code, Division 13, Part 2.3, commencing
with Section 18860 and California Code of
Regulations, Title 25, Division 1, Chapter 2.2,
commencing with Section 2000.

4. For applications subject to the Employee
Housing Act as referenced in Section 89.108.3.2.4

of this code, refer to Health and Safety Code,
Division 13, Part 1, commencing with Section
17000 and California Code of Regulations, Title
25, Division 1, Chapter 1, Subchapter 3,
commencing with Section 600.

5. For applications subject to the Factory-Built
Housing Law as referenced in Section 89.108.3.2.5
of this code, refer to Health and Safety Code,
Division 13, Part 6, commencing with Section
19960 and California Code of Regulations, Title
25, Division 1, Chapter 3, Subchapter 1,
commencing with Section 3000.

89.108.6 LOCAL MODIFICATION BY ORDINANCE
OR REGULATION

89.108.6.1 General. Subject to other provisions of
law, a city, county or city and county may make
changes to the provisions adopted by the Department
of Housing and Community Development. If any city,
county or city and county does not amend, add, or
repeal by local ordinances or regulations the
provisions published in this code or other regulations
promulgated by the Department of Housing and
Community Development, those provisions shall be
applicable and shall become effective 180 days after
publication by the California Building Standards
Commission. Amendments, additions and deletions to
this code adopted by a city, county or city and county
pursuant to California Health and Safety Code
Sections 17958.5, 17958.7 and 18941.5, together
with all applicable portions of this code, shall also
become effective 180 days after publication of the
California Building Standards Code by the
California Building Standards Commission.

89.108.6.2 Findings, Filings, and Rejections of Local
Modifications, Prior to making any modifications or
establishing more restrictive building standards, the
governing body shall make express findings and filings,
as required by California Health and Safety Code
Section 17958.7, showing that such modifications are
reasonably necessary due to local climatic, geological,
or topographical conditions. No modification shall
become effective or operative unless the following
requirements are met:

1. The express findings shall be made available
as a public record.

2. A copy of the modification and express
finding, each document marked to cross-
reference the other, shall be filed with the
California Building Standards Commission for a
city, county or city and county and with the
Department of Housing and Community
Development for fire protection districts.

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3. The California Building Standards Commission
has not rejected the modification or change.

Nothing in this section shall limit the authority of fire
protection districts pursuant to California Health and
Safety Code Section 13869. 7 (a).

89.108.7 ALTERNATE MATERIALS, DESIGNS,
TESTS AND METHODS OF CONSTRUCTION

89.108.7.1 General. The provisions of this code
as adopted by the Department of Housing and
Community Development are not intended to
prevent the use of any alternate material,
appliance, installation, device, arrangement,
design or method of construction not specifically
prescribed by this code. Consideration and
approval of alternates shall comply with Section

89.108.7.2 for local building departments and
Section 89.108.7.3 for the Department of Housing
and Community Development.

89.108.7.2 Local Building Departments. The

building department of any city, county or city and
county may approve alternates for use in the
erection, construction, reconstruction, movement,
enlargement, conversion, alteration, repair, removal,
demolition or arrangement of an apartment house,
hotel, motel, lodging house, dwelling, or an
accessory structure, except for the following:

1. Structures located in mobilehome parks as defined
in California Health and Safety Code Section 18214.

2. Structures located in special occupancy parks as
defined in California Health and Safety Code Section
18862.43.

3. Factory-built housing as defined in California
Health and Safety Code Section 19971.

89.108.7.2.1 Approval of Alternates. The

consideration and approval of alternates by a local
building department shall comply with the following
procedures and limitations:

1. The cpproval shall be granted on a case-by-case basis.

2. Evidence shall be submitted to substantiate claims
that the proposed alternate, in performance, safety, and
protection of life and health, conforms to, or is at least
equivalent to, the standards contained in this code and
other rules and regulations promulgated by the
Department of Housing and Community Development

3. The local building department may require
tests performed by an approved testing agency at
the expense of the owner or owner 's agent as
proof of compliance.

4. If the proposed alternate is related to accessibility in
covered multifamily dwellings or in facilities serving
''COVERED MULTIFAMILY DWELLINGS'' as
defined in CBC Chapter 11 A, the proposed alternate

must also meet the threshold set for ''EQUIVALENT
FACILITATION'' as defined in CBC Chapter 11 A.

For additional information regarding approval of
alternates by a local building department pursuant
to the State Housing Law, see California Health
and Safety Code Section 17951(e) and California
Code of Regulations, Title 25, Division 1, Chapter
1, Subchapter 1.

89.108.7.3 Department of Housing and Community
Development. The Department of Housing and
Community Development may approve alternates for
use in the erection, construction, reconstruction,
movement, enlargement, conversion, alteration,
repair, removal or demolition of an apartment house,
hotel, motel, lodging house, dwelling, or an
accessory thereto. The consideration and approval of
alternates shall comply with the following:

1. The department may require tests at the expense of
the owner or owner 's agent to substantiate compliance
with the California Building Standards Code.

2, The approved alternate . shall, for its intended
purpose, be at least equivalent in performance and
safety to the materials, designs, tests, or methods of
construction prescribed by this code.

89.108.8 APPEALS BOARD

89.108.8.1 General. Every city, county or city and
county shall establish a local appeals board and a
housing appeals board. The local appeals board and
housing appeals board shall each be comprised of at
least five voting members who shall serve at the
pleasure of the city, county or city and county.
Appointees shall not be employees of the jurisdiction
and shall be qualified and specifically knowledgeable
in the California Building Standards Codes and
applicable local ordinances.

89.108.8.2 Definitions. The following terms shall for
the purposes of this section have the meaning shown.

Housing Appeals Board. The board or agency of a
city, county or city and county which is authorized by
the governing body of the city, county or city and
county to hear appeals regarding the requirements of
the city, county or city and county relating to the use,
maintenance and change of occupancy of buildings
and structures, including requirements governing
alteration, additions, repair, demolition, and moving.
In any area in which there is no such board or
agency, ''Housing Appeals Board" means the local
appeals board having jurisdiction over the area.

Local Appeals Board. The board or agency of a city,
county or city and county which is authorized by the
governing body of the city, county or city and county
to hear appeals regarding the building requirements
of the city, county or city and county. In any area in

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which there is no such board or agency, "Local
Appeals Board'' means the governing body of the
city, county or city and county having jurisdiction
over the area.

89,108.8.3 Appeals. Except as otherwise provided by
law, any person, firm, or corporation adversely
affected by a decision, order, or determination by a
city, county or city and county relating to the
application of building standards published in the
California Building Standards Code, or any other
applicable rule or regulation adopted by the
Department of Housing and Community
Development, or any lawfully enacted ordinance by a
city, county or city and county, may appeal the issue
for resolution to the local appeals board or housing
appeals board as appropriate.

The local appeals board shall hear appeals relating to
new building construction and the housing appeals board
shall hear appeals relating to existing buildings.

89.108.9 UNSAFE BUILDINGS OR STRUCTURES

89.108.9,1 Authority to Enforce. Subject to other
provisions of law, the administration, enforcement,
actions, proceedings, abatement, violations and penalties
for unsafe buildings and structures are contained in the
following statutes and regulations:

1. For applications subject to State Housing Law as
referenced in Section 89.108.3.2.1 of this code, refer to
Health and Safety Code, Division 13, Part 1.5,
commencing with Section 17910 and California Code
of Regulations, Title 25, Division 1, Chapter 1,
Subchapter 1, commencing with Section 1.

2. For applications subject to the Mobilehome Parks
Act as referenced in Section 89.108.3.2.2 of this code,
refer to Health and Safety Code, Division 13, Part 2.1,
commencing with Section 18200 and California Code
of Regulations, Title 25, Division 1, Chapter 2,
commencing with Section 1000.

3. For applications subject to the Special Occupancy
Parks Act as referenced in Section 89.108.3.2.3 of this
code, refer to Health and Safety Code, Division 13,
Part 2.3, commencing with Section 18860 and
California Code of Regulations, Title 25, Division 1,
Chapter 2.2, commencing with Section 2000.

4. For applications subject to the Employee Housing
Act as referenced in Section 89.108.3.2.4 of this code,
refer to Health and Safety Code, Division 13, Part 1,
commencing with Section 17000 and California Code
of Regulations, Title 25, Division 1, Chapter 1,
Subchapter 3, commencing with Section 600.

Code of Regulations, Title 25, Division 1, Chapter 3,
Subchapter 1, commencing with Section 3000.

89.108.9.2 Actions and Proceedings. Subject to other
provisions of law, punishments, penalties and fines for
violations of building standards are contained in the
following statutes and regulations:

1. For applications subject to State Housing Law as
referenced in Section 89.108.3.2.1 of this code, refer to
Health and Safety Code, Division 13, Part 1.5,
commencing with Section 17910 and California Code
of Regulations, Title 25, Division 1, Chapter 1,
Subchapter 1, commencing with Section 1.

3. For applications subject to the Special Occupancy
Parks Act as referenced in Section 89.108.3.2.3 of this
code, refer to Health and Safety Code, Division 13,
Part 2.3, commencing with Section 18860 and
California Code of Regulations, Title 25, Division 1,
Chapter 2.2, commencing with Section 2000.

4. For applications subject to the Employee Housing
Act as referenced in Section 89.108.3.2.4 of this code,
refer to Health and Safety Code, Division 13, Part 1,
commencing with Section 1 7000 and California Code
of Regulations, Title 25, Division 1, Chapter 1,
Subchapter 3, commencing with Section 600.

5. For applications subject to the Factory-Built Housing
Law as referenced in Section 89.108.3.2.5 of this code,
refer to Health and Safety Code, Division 13, Part 6,
commencing with Section 19960 and California Code of
Regulations, Title 25, Division 1, Chapter 3, Subchapter
1, commencing with Section 3000.

89.108.10 OTHER BUILDING REGULATIONS

89.108.10.1 Existing Structures. Subject to the
requirements of California Health and Safety Code
Sections 17912, 17920.3, 17922, 17922.3, 17958.8 and
17958.9, the provisions contained in Chapter 34 of the
CBC relating to existing structures shall only apply as
identified in the Matrix Adoption Table under the
authority of the Department of Housing and Community
Development as listed in Sections 89.108.2.1.1 through
89108.2.1.3 of this code.

89.108.10.2 Moved Structures. Subject to the
requirements of California Health and Safety Code
Sections 17922.3 and 17958.9, the provisions relating to
a moved residential structure shall, after July 1, 1978,
permit the retention of existing materials and methods of
construction so long as the structure does not become or
continue to be a substandard building.

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SECTION 89 J09

DIVISION OF THE STATE ARCHITECT

89.109.1 DSA— AC — Division of the State Architect-Access
Compliance.

Note: For applications listed in Section 1.9.1 of the
California Building Code, regulated by the Division of
the State Architect—Access Compliance see California
Code of Regulations, Title 24, Part 2 (California Building
Code), Chapter 1 (Division 1 California Administration)
under authority cited by Government Code Section 4450
and in reference cited by Government Code Sections
4450, through 4461, 12955.1 and Health and Safety Code
Sections 18949 J, 19952 through 19959.

89.109.2 DSA-SS - Division of the State Architect -
Structural Safety.

89.109.2.1. DSA-SS (Division of the State
Architect - Structural Safety)

1. Application - Public elementary and secondary
schools, community college buildings, and state-owned
or state-leased essential services buildings.

Enforcing Agency ~ Division of the State Architect -
Structural Safety (DSA-SS).

The Division of the State Architect has been delegated
the responsibility and authority by the Department of
General Services to review and approve the design and
oversee the construction of public elementary and
secondary schools, community colleges, and state-
owned or state-leased essential services buildings.

Authority Cited - Education Code section 17310 and
81142, and Health and Safety Code section 16022.

Reference - Education Code Sections 17280 through
17317 and 81 130 through 81147, and Health & Safety
Code Sections 16000 through 16023.

89.109.2.2. DSA'SS/CC (Division of the State
Architect - Structural Safety/Community Colleges)

Application - Community Colleges.

The Division of the State Architect has been
delegated the authority by the Department of General
Services to promulgate alternate building standards
for application to community colleges, which a
community college may elect to use in lieu of
standards promulgated by DSA-SS in accordance
with Section 89. 109.2. L Refer to Title 24, Part 2,
Section 1.9.2.2.

Enforcing Agency - Division of the State Architect ~
Structural Safety/Community Colleges (DSA-SS/CC)

The Division of the State Architect has been
delegated the authority by the Department of General
Services to review and approve the design and

oversee construction of community colleges electing
to use the alternative building standards as provided
in this section.

Authority Cited - Education Code Section 81053.

Reference - Education Code Sections 81052, 81053,
and 81 130 through 81147.

89.109.3 SHE - State Historical Building Safety Board.

See California Code of Code of Regulations, Title 24,
Part 8 (California Historical Building Code).

SECTION 89.110

OFFICE OF STATEWIDE HEALTH PLANNING
AND DEVELOPMENT

89.110.1. OSHPD 1. Specific scope of application of the
agency responsible for enforcement, enforcement agency,
specific authority to adopt and enforce such provisions of this
code, unless otherwise stated.

OSHPD 1

Application - General acute-care hospitals and acute
psychiatric hospitals, excluding distinct part units or
distinct part freestanding buildings providing skilled
nursing or intermediate-care services. For Structural
Regulations: Skilled nursing facilities and/or
intermediate-care facilities except those skilled nursing
facilities and intermediate care facilities of single story.
Type V, wood or light steel-frame construction.

Enforcing Agency -Office of Statewide Health Planning
and Development (OSHPD). The office shall enforce the
Division of the State Architect access compliance
regulations and the regulations of the Office of the State
Fire Marshal for the above stated facility types.

89. 110. 1. 1 Applicable administrative standards.

1. Title 24, Part 1, California Code of Regulations:
Chapters 6 &7.

2. Title 24, Part 2, California Code of Regulations:
Sections 101 and 110 of California Chapter 1 and
Appendix Chapter 1.

89.110.1.2 Applicable building standards.

California Building Standards Code, Title 24, Parts
2,3,4, 5,9, 10 and 12,

89.110.2. OSHPD 2. Specific scope of application of the
agency responsible for enforcement, enforcement agency,
specific authority to adopt and enforce such provisions of
this code, unless otherwise stated,

OSHPD 2

Application —Skilled nursing facilities and intermediate-
care facilities, including distinct part skilled nursing and
intermediate-care services on a general acute-care or
acute psychiatric hospital license, provided either in a
separate unit or a freestanding building. For Structural

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Regulations: Single-story, Type V skilled nursing facility
and/or intermediate-care facilities utilizing wood or light
steel-frame construction.

Enforcing Agency — Office of Statewide Health Planning
and Development (OSHPD). The office shall also enforce the
Division of the State Architect access compliance regulations
and the regulations of the Office of the State Fire Marshal for
the above stated facility type.

89.110.2.1 Applicable administrative standards:

I- Title 24, Part 7, California Code of Regulations:
Chapter 7.

2. Title 24, Part 2] California Code of Regulations:
Sections 101 and 1 ] of California Chapter 1 and
Appendix Chapter 1 .

89.110.2.2 Applicable building standards.

California Building Standards Code, Title 24, Parts
2,3,4,5,9, 10 and 12.%'

89. 110. 3. OSHPD 3. Specific scope of application of the

agency responsible for enforcement, enforcement agency,
specific authority to adopt and enforce such provisions of
this code; unless otherwise seated.

OSHPD J

Application —Licensed clinics and any freestanding
building under a hospital license where outpatient
clinical services are provided. :■

Enforcing Agency--Local building department.

89.110.3.1 Applicable administrative standards.

1. Title 24, Part 1, California Code of Regulations:
Chapter 7.

2. Title 24, Part 2, California Code of Regulations:
Sections 101 arid 110 of California Chapter 1 and
Appendix Chapter I.

89.110.3.2 Applicable building standards.

California Building Standards Code, Title 24, Parts
2,3,4,5,9, IV and 12. ' ^

89.110.4. OSHPD 4. Specific scope of application of the
agency responsible for enforcement, enforcement agency,
specific authority to adopt and enforce such provisions of
this code, unless otherwise stated.

OSHPD 4

Application —Correctional Treatment Centers.

Enforcing Agency ~ Office of Statewide Health Planning
arid Development (OSHPD). The Office shall also enforce
the Division of the State Architect access compliance
regulations and the regulations of the Office of the State
Fire Marshal for the above stated facility types.

89.110.4.1 Applicable administrative standards.

I. Title 24, Part 1, California Code of Regulations:
Chapter 7.

2. Title 24, Part 2, California Code of Regulations:
Sections 101 and 110 of California Chapter 1 and
Appendix Chapter 1.

89.110.4.2 Applicable building standards. California
Building Standards Code, Title 24, Parts 2, 3, 4, 5, 9, 10
and 12.

SECTION 89.111
OFFICE OF THE STATE FIRE MARSHAL

89.111.1 SFM— Office of the State Fire Marshal.

Specific scope of application of the agency responsible for
enforcement, the enforcement agency and the specific
authority to adopt and enforce such provisions of this
code, unless otherwise stated.

Application:

Institutional, educational or any similar occupancy. Any

building or structure used or intended for use as an
asylum, jail, mental hospital, hospital, sanitarium, home
for the aged, children *s nursery, children 's home, school
or any similar occupancy of any capacity.

Authority cited-^Health and Safety Code Section 13143.

Reference — Health and Safety Code Section 13143.

Assembly or similar place of assemblage. Any theater,
dancehall, skating rink, auditorium, assembly hall,
meeting hall, nightclub, fair building or similar place of
assemblage where 50 or more persons may gather
together in a building, room or structure for the purpose
of amusement, entertainment, instruction, deliberation,
worship, drinking or dining, awaiting transportation, or
education.

Authority cited — Health and Safety Code Section 13143.

Reference — Health and Safety Code Section 13143.

Small family day care homes.

Authority cited — Health and Safety Code Sections

1597.45, 1597.54, 13143 and 17921.

Reference - Health and Safety Code Section 13143.
Large family day care homes.

Authority cited — Health and Safety Code Sections

1597.46, 1597.54 and 17921.

Reference - Health and Safety Code Section 13143.

Residential facilities and residential facilities for the
elderly.

Authority cited — Health and Safety Code Section 13133.

Reference — Health and Safety Code Section 13143.

Any state institution or other state-owned or state-
occupied building.

Authority cited— Health and Safety Code Section 13108.

Reference — Health and Safety Code Section 13143.

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High-rise structures.

Authority cited— Health and Safety Code Section 13211.

Reference — Health and Safety Code Section 13143.

Motion picture production studios.

Authority cited — Health and Safety Code Section 13143.1.

Reference — Health and Safety Code Section 13143.

Organized camps.

Authority cited— Health and Safety Code Section 18897.3.

Reference — Health and Safety Code Section 13143.

Residential All hotels, motels, lodging houses, apartment
houses and dwellings, including congregate residences and
buildings and structures accessory thereto. Multiple-story
structures existing on January 1, 1975, let for human
habitation, including and limited to, hotels, motels and
apartment houses, less than 75 feet (22 860 mm) above the
lowest floor level having building access, wherein rooms
used for sleeping are let above the ground floor.

Authority cited — Health and Safety Code Sections
13143.2 and 17921.

Reference — Health and Safety Code Section 13143.

Residential care facilities. Certified family care homes,
out-of-home placement facilities, halfway houses, drug
and/or alcohol rehabilitation facilities and any building
or structure used or intended for use as a home or
institution for the housing of any person of any age when
such person is referred to or placed within such home or
institution for protective social care and supervision
services by any governmental agency.

Authority cited — Health and Safety Code Section 13143.6,

Reference — Health and Safety Code Section 13143.

Tents, awnings or other fabric enclosures used in
connection with any occupancy.

Authority cited — Health and Safety Code Section 13116.

Reference — Health and Safety Code Section 13143.

Fire alarm devices, equipment and systems in
connection with any occupancy.

Authority cited— Health and Safety Code Section 13114.

Reference — Health and Safety Code Section 13143.

Hazardous materials.

Authority cited — Health and Safety Code Section 13143.9.

Reference — Health and Safety Code Section 13143.

Flammable and combustible liquids.

Authority cited — Health and Safety Code Section 13143.6.

Reference — Health and Safety Code Section 13143.

Public School Automatic Fire Detection, Alarm and
Sprinkler Systems.

Authority cited — Health and Safety Code Section 13143
and California Education Code Article 7.5, Sections
17074.50, 17074.52 and 17074.54.

Reference — Government Code Section 11152.5, Health
and Safety Code Section 13143 and California Education
Code Chapter 12.5, Leroy F. Greene School Facilities Act
of 1998, Article 1.

Wildland-Urban Interface Fire Area.

Authority cited — Health and Safety Code Sections 13143,
13108.5(a) and 18949.2(b) and (c) and Government Code
Section 51189.

Reference — Health and Safety Code Sections 13143,
Government Code Sections 51176, 51177, 51178 and
51179 and Public Resources Code Sections 4201 through
4204.

89. 111. 2 Duties and Powers of the Enforcing Agency

89.111.2.1 Enforcement.

89.111.2.1.1 The responsibility for enforcement of
building standards adopted by the State Fire
Marshal and published in the California Building
Standards Code relating to fire and panic safety
and other regulations of the State Fire Marshal
shall except as provided in Section 89.111.2.1.2 be
as follows:

1. The city, county or city and county with
jurisdiction in the area affected by the standard
or regulation shall delegate the enforcement of
the building standards relating to fire and panic
safety and other regulations of the State Fire
Marshal as they relate to Group R-3
occupancies, as described in Section 310.1 of
Part 2 of the California Building Standards
Code, to either of the following:

1.1. The chief of the fire authority of the city, county
or city and county, or an authorized representative.

1.2. The chief building official of the city, county or
city and county, or an authorized representative.

2. The chief of any city or county fire department
or of any fire protection district, and authorized
representatives, shall enforce within the
jurisdiction the building standards and other
regulations of the State Fire Marshal, except
those described in Item 1 or 4.

3. The State Fire Marshal shall have authority to
enforce the building standards and other
regulations of the State Fire Marshal in areas
outside of corporate cities and districts
providing fire protection services.

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4, The State Fire Marshal shall have authority to
enforce the building standards -and other
regulations of the State: Fire Marshal in
corporate cities and districts providing fire
protection services on request of the chief fire
official or the governing body.

5. Any fee charged pursuant to the enforcement
authority of this section shall not exceed the
estimated reasonable cost of providing the
service for which the fee is charged pursuant to
Section 66014 of the Government Code.

89,111.2,1,2 Pursuant to Health and Safety Code
Section 13108, and except as otherwise provided in
this section, building standards adopted by the
State Fire Marshal published in the California
Building Standards Code relating to fire and panic
safety shall be enforced by the State Fire Marshal
in all state-owned buildings, state-occupied
buildings, and state institutions throughout the
state. Upon the written request of the chief fire
official of any city, county or fire protection
district, the State Fire Marshal may authorize such
chief fire official and his or her authorized
representatives, in their geographical area of
responsibility, to make fire prevention inspections
of state-owned or state-occupied buildings, other
than state institutions, for the purpose of enforcing
the regulations relating to fire and panic safety
adopted by the State Fire Marshal pursuant to this
section and building standards relating to fire and
panic safety published in the California Building
Standards Code. Authorization from the State Fire
Marshal shall be limited to those fire departments
or fire districts which maintain a fire prevention
bureau staffed by paid personnel.

Pursuant to Health and Safety Code Section 13108,
any requirement or order made by any chief fire
official who is authorized by the State Fire
Marshal to make fire prevention inspections of
state-owned or state-occupied buildings, other than
state institutions, may be appealed to the State Fire
Marshal. The State Fire Marshal shall, upon
receiving an appeal and subject to the provisions
of Chapter 5 (commencing with Section 18945) of
Part 2.5 of Division 13 of the Health and Safety
Code, determine if the requirement or order made
is reasonably consistent with the fire and panic
safety regulations adopted by the State Fire
Marshal and building standards relating to fire
and panic safety published in the California
Building Code.

Any person may request a code interpretation from
the State Fire Marshal relative to the intent of any
regulation or provision adopted by the State Fire

Marshal When the request relates to a specific
project, occupancy or building, the State Fire
Marshal shall review the issue with the appropriate
local enforcing agency prior to rendering such
code interpretation.

89,111,2.1,3 Pursuant to Health and Safety Code
Section 13112, any person who violates any order,
rule or regulation of the state fire marshal is guilty
of a misdemeanor punishable by a fine of not less
than $100.00 or more than $500,00, or by
imprisonment for not less than six months, or by
both. A person is guilty of a separate offense each
day during which he or she commits, continues or
permits a violation of any provision of or any
order, rule or regulation of the state fire marshal
as contained in this code.

Any inspection authority who, in the exercise of his
or her authority as a deputy state fire marshal,
causes any legal complaints to be filed or any
arrest to be made shall notify the state fire marshal
immediately following such action,

89.111.2.2 Right of entry.

The fire chief of any city, county or fire-protection
district, or such person 's authorized representative,
may enter any state institution or any other state-
owned or state-occupied building for the purpose of
preparing a fire-suppression preplanning program or
for the purpose of investigating any fire in a state-
occupied building.

The State Fire Marshal, his or her deputies or
salaried assistants, the chief of any city or county fire
department or fire protection district and his or her
authorized representatives may enter any building or
premises not used for dwelling purposes at any
reasonable hour for the purpose of enforcing this
chapter. The owner, lessee, manager or operator of
any such building or premises shall permit the State
Fire Marshal, his or her deputies or salaried
assistants and the chief of any city or county fire
department or fire-protection district and his or her
authorized representatives to enter and inspect them
at the time and for the purpose stated in this section,

89.111.2.3 More Restrictive Fire and Panic Safety
Building Standards,

89.111.2.3.1 Any fire-protection district organized
pursuant to Health and Safety Code Part 2.7
(commencing with Section 13800) of Division 12
may adopt building standards relating to fire and
panic safety that are more stringent than those
building standards adopted by the State Fire
Marshal and contained in the California Building
Standards Code. For these purposes, the district
. hoard shall be deemed a legislative body and the

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district shall be deemed a local agency. Any
changes or modifications that are more stringent
than the requirements published in the California
Building Standards Code relating to fire and panic
safety shall be subject to 101.8.1.

89.111.2.3.2 Any fire protection district that
proposes to adopt an ordinance pursuant to this
section shall, not less than 30 days prior to noticing
a proposed ordinance for public hearing, provide a
copy of that ordinance, together with the adopted
findings made pursuant to Section 89.111.2.3.1, to
the city, county, or city and county where the
ordinance will apply. The city, county, or city and
county, may provide the district with written
comments, which shall become part of the fire
protection district's public hearing record.

89.111.2.3.3 The fire-protection district shall
transmit the adopted ordinance to the city, county,
or city and county where the ordinance will apply.
The legislative body of the city, county, or city and
county, may ratify, modify or deny an adopted
ordinance and transmit its determination to the
district within 15 days of the determination. Any
modification or denial of an adopted ordinance shall
include a written statement describing the reasons
for any modifications or denial. No ordinance
adopted by the district shall be effective until
ratification by the city, county, or city and county
where the ordinance will apply. Upon ratification of
an adopted ordinance, the city, county, or city and
county, shall file a copy of the findings of the
district, and any findings of the city, county, or city
and county, together with the adopted ordinance
expressly marked and identified to which each
finding refers, in accordance with Section 101.8.1:3.

89.111.2.4 Request for alternate means of protection.

Requests for approval to use an alternative material,
assembly or materials, equipment, method of
construction, method of installation of equipment, or
means of protection shall be made in writing to the
enforcing agency by the owner or the owner's
authorized representative and shall be accompanied
by a full statement of the conditions. Sujficient
evidence or proof shall be submitted to substantiate
any claim that may be made regarding its
conformance. The enforcing agency may require tests
and the submission of a test report from an approved
testing organization as set forth in Title 19, California
code of Regulation, to substantiate the equivalency of
the proposed alternative means of protection.

The authority having jurisdiction may consider
implementation of the findings and recommendations
identified in a Risk Management Plan (RMP) as
developed in accordance with Title 19, Division 2,

Chapter 3, when evaluating requests for alternative
means of protection.

Approval of a request for use of an alternative
material, assembly of materials, equipment, method of
construction, method of installation of equipment, or
means of protection made pursuant to these provisions
shall be limited to the particular case covered by
request and shall not be construed as establishing any
precedent for any future request.

89.111.2.5 Appeals. When a request for an alternate
means of protection has been denied by the enforcing
agency, the applicant may file a written appeal to the
state fire marshal for consideration of the applicant's
proposal. In considering such appeal, the state fire
marshal may seek the advice of the State Board of Fire
Services. The State Fire Marshal shall, after
considering all of the facts presented, including any
recommendations of the State board of Fire Services,
determine if the proposal is for the purposes intended,
at least equivalent to that specified in these regulations
in quality, strength, effectiveness, fire resistance,
durability and safety, and shall transmit such findings
and any recommendations to the applicant and to the
enforcing agency.

89.111.3 Construction Documents. In addition to the
provisions of this Section, see Title 24, Part 2, California
Building Code, Appendix Chapter 1, Section 106 for
additional requirements.

89.111.3.1 Public schools. Plans and specifications
for the construction, alteration or addition to any
building owned, leased or rented by any public school
district shall be submitted to the Division of the State
Architect.

89.111.3.2 Movable walls and partitions. Plans or
diagrams shall be submitted to the enforcing agency
for approval before the installation of, or
rearrangement of, any movable wall or partition in
any occupancy. Approval shall be granted only if there
is no increase in the fire hazard.

89.111.3.3 New construction high-rise buildings.

1. Complete plans or specifications, or both, shall be
prepared covering all work required to comply with
new construction high-rise buildings. Such plans
and specifications shall be submitted to the
enforcing agency having jurisdiction.

2. All plans and specifications shall be prepared
under the responsible charge of an architect or a
civil or structural engineer authorized by law to
develop construction plans and specifications, or by
both such architect and engineer. Plans and
specifications shall be prepared by an engineer duly
qualified in that branch of engineering necessary to
perform such services. Administration of the work of

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2010 California Electrical Code

70-15

CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

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construction shall be under the charge of the
responsible architect or engineer except that where
plans and specifications involve alterations or
repairs, such work of construction may be
administered by an engineer duly qualified to
perform such services and holding a valid certificate
under Chapter 7 (commencing with Section 65700)
of Division 3 of the Business and Professions Code
for performance of services in that branch of
engineering in which said plans, specifications and
estimates and work of construction are applicable.

This section shall not be construed as preventing the
design of fire-extinguishing systems by persons
holding a C-16 license issued pursuant to Division
3, Chapter 9, Business and Professions Code. In
such instances, however, the responsibility charge of
this section shall prevail,

89,11L3,4 Existing high-rise buildings, 1. Complete
plans or specifications, or both, shall be prepared
covering all work required by Section 3412, for
existing high-rise buildings. Such plans or
specifications shall be submitted to the enforcing
agency having jurisdiction.

2. When new construction is required to conform
with the provisions of these regulations, complete
plans or specifications, or both, shall be prepared in
accordance with the provisions of this subsection. As
used in this section ''new construction" is not
intended to include repairs, replacements or minor
alterations which do not disrupt or appreciably add
to or affect the structural aspects of the building,

89,111,3,5 Retention of Plans, Refer to Building
Standards Law, Health and Safety Code Sections
19850 and 19851, for permanent retention of plans.

89.111,4 Fees

89.111.4.1 Other fees. Pursuant to Health and Safety
Code Section 13146.2, a city, county or district which
inspects a hotel, motel, lodging house, or apartment
house may charge and collect a fee for the inspection
from the owner of the structure in an amount, as
determined by the city, county or district, sufficient to
pay its costs of that inspection.

89.111.4.2 Large Family Day Care, Pursuant to
Health and Safety Code Section 1597.46, Large
Family Day-care Homes, the local government shall
process any required permit as economically as
possible, and fees charged for review shall not exceed
the costs of the review and permit process.

89.111.4.3 High-Rise, Pursuant to Health and Safety
Code Section 1321 7, High-rise Structure Inspection: Fees
and Costs, a local agency which inspects a high-rise
structure pursuant to Health arid Safety Code Section
1321 7 may charge and collect a fee for the inspection

from the owner of the high-rise structure in an amount, as
determined by the local agency, sufficient to pay its costs
of that inspection,

89.111.4.4 Fire Clearance Preinspection, Pursuant to
Health and Safety Code Section 13235, Fire Clearance
Preinspection, fee; upon receipt of a request from a
prospective licensee of a community care facility, as
defined in Section 1502, of a residential-care facility for
the elderly, as defined in Section 1569,2, or of a child
day-care facility, as defined in Section 1596, 750, the local
fire enforcing agency, as defined in Section 13244, or
state fire marshal, whichever has primary jurisdiction,
shall conduct a preinspection of the facility prior to the
final fire clearance approval At the time of the
preinspection, the primary fire enforcing agency shall
price consultation and interpretation of the fire safety
regulations, and shall notify the prospective licensee of
the facility in writing of the specific fire safety regulations
which shall be enforced in order to obtain fire clearance
approval A fee equal to, but not exceeding, the actual
cost of the preinspection services may be charged for the
preinspection of a facility with a capacity to serve 25 or
fewer persons. A fee equal to, but not exceeding, the
actual cost of the preinspection services may be charged
for a preinspection of a facility with a capacity to serve 26
or more persons,

89.111.4.5 Care Facilities, The primary fire enforcing
agency shall complete the final fire clearance inspection
for a community care facility, residential-care facility for
the elderly, or child day-care facility within 30 days of
receipt of the request for the final inspection, or as of the
date the prospective facility requests the final
prelicensure inspection by the State Department of Social
Services, whichever is later.

Pursuant to Health and Safety Code Section 13235, a
preinspection fee equal to, but not exceeding, the actual
cost of the preinspection services may be charged for a
facility with a capacity to serve 25 or less clients. A fee
equal to, but not exceeding, the actual cost of the
preinspection services may be charged for a
preinspection of a facility with a capacity to serve 26 or
more clients.

Pursuant to Health and Safety Code Section 1313L5, a
reasonable final inspection fee, not to exceed the actual
cost of inspection services necessary to complete a final
inspection may be charged for Occupancies classified as
residential care facilities for the elderly (RCFE).

Pursuant to Health and Safety Code Section 1569.84,
neither the state fire marshal nor any local public entity
shall charge any fee for enforcing fire inspection
regulations pursuant to state law or regulation or local
ordinance, with respect to residential-care facilities for
the elderly (RCFE) which service six or fewer persons.

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70-16

2010 California Electrical Code

CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS

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89.111.4.6 Requests of the Office of the State Fire
Marshal Requests, Whenever a local authority having
jurisdiction requests that the State Fire Marshal
perform plan review and/or inspection services related
to a building permit, the applicable fees for such shall
be payable to the Office of the State Fire Marshal

89.111.5 Inspections. Work performed subject to the
provisions of this code shall comply with the inspection
requirements of Title 24, Part 2, California Building
Standards Code, Sections 109.1, 109.3, 109.3.4, 109.3.5,
109.3.6, 109.3.8, 109.3.9, 109.3.10 109.5 and 109.6 as
adopted by the Office of the State Fire Marshal

89.111.5.1 Existing Group I-l or R occupancies.

Licensed 24-hour care in a Group I-l or R occupancy
in existence and originally classified under
previously adopted state codes be reinspected under
the appropriate previous code provided there is no
change in the use or character which would place the
facility in a different occupancy group.

89.111.6 Certificate of Occupancy. A Certificate of
Occupancy shall be issued as specified in Title 24, Part
2, California Building Code, Section 111.

Exception: Group R, Division 3 and Group U

occupancies.

89.111.7 Temporary Structures and Uses. See Title 24,
Part 2, California Building Code, Section 107.

89.111.8 Service Utilities. See Title 24, Part 2, California
Building Code Sectionll2.

89.111.9 Stop Work Order. See Title 24, Part 2,
California Building Code, Section 115.

89.111.10 Unsafe Buildings, Structures and Equipment. See

Title 24, Part 2, California Building Code, Section 116.

SECTION 89.112

RESERVED FOR THE STATE LIBRARIAN

SECTION 89.113

RESER VED FOR THE DEPARTMENT OF WA TER
RESOURCES

SECTION 89.114

RESERVED FOR THE CALIFORNIA STATE
LANDS COMMISSION

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2010 California Electrical Code

70-17

ARTICLE 90 - CALIFORNIA MATRIX ADOPTION TABLE

70-18 2010 California Electrical Code

ARTICLE 90 CALIFORNIA MATRIX ADOPTION TABLE

ARTICLE 90 - INTRODUCTION

Adopting Agency

BSC

SFM

HCD

DSA

OSHPD

DPH

ss/cc

Adopt Entire Article

Adopt Entire Article as amended
(amended sections listed below)

Adopt only those articles / sections that
are listed below

Article / Section

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.
20 iO California Electrical Code 70-19

ARTICLE 90 - CALIFORNIA MATRIX ADOPTION TABLE

70-20 20 10 California Electrical Code

ARTICLE 90 - INTRODUCTION

90.2

NFPA 70

National Electrical Code®

2008 Edition

IMPORTANT NOTE: This NFPA document is made
available for use subject to important notices and legal
disclaimers. These notices and disclaimers appear in all
publications containing this document and may be found
under the heading '^Important Notices and Disclaimers
Concerning NFPA Documents,^' They can also be
obtained on request from NFPA or viewed at
www, nfpa, org/disclaimers,

90.1 Purpose.

(A) Practical Safeguarding. The purpose of this Code is
the practical safeguarding of persons and property from
hazards arising from the use of electricity.

(B) Adequacy. This Code contains provisions that are
considered necessary for safety. CompHance therewith and
proper maintenance results in an installation that is essentially
free from hazard but not necessarily efficient, convenient, or
adequate for good service or ftiture expansion of electrical use.

FPN: Hazards often occur because of overloading of wiring
systems by methods or usage not in conformity with this
Code. This occurs because initial wiring did not provide for
increases in the use of electricity. An initial adequate
installation and reasonable provisions for system changes
provide for future increases in the use of electricity.

(D) Relation to Other International Standards. The

requirements in this Code address the fundamental
principles of protecfion for safety contained in Section 131
of International Electrotechnical Commission Standard
60364-1, Electrical Installations of Buildings,

FPN: lEC 60364-1, Section 131, contains fundamental
principles of protection for safety that encompass protection
against electric shock, protection against thermal effects,
protection against overcurrent, protection against fault currents,
and protection against overvoltage. All of these potential
hazards are addressed by the requirements in this Code.

90.2 Scope.

(A) Covered. This Code covers the installation of electrical
conductors, equipment, and raceways; signaling and
communications conductors, equipment, and raceways; and
optical fiber cables and raceways for the following:

(1) Pubhc and private premises, including buildings, structures,
mobile homes, recreational vehicles, and floating buildings

(2) Yards, lots, parking lots, carnivals, and industrial
substations

# (3) Installations of conductors and equipment that connect
to the supply of electricity
(4) Installations used by the electric utility, such as office
buildings, warehouses, garages, machine shops, and
recreational buildings, that are not an integral part of a
generating plant, substafion, or control center.

(B) Not Covered. This Code does not cover the following:

(1) Installations in ships, watercraft other than floating
buildings, railway rolUng stock, aircraft, or automotive
vehicles other than mobile homes and recreational
vehicles

FPN: Although the scope of this Code indicates that the
Code does not cover installations in ships, portions of this
Code are incorporated by reference into Title 46, Code of
Federal Regulations, Parts 1 1 0-1 1 3 .

(2) Installations underground in mines and self-propelled
mobile surface mining machinery and its attendant
electrical trailing cable

(3) Installations of railways for generation, transformation,
transmission, or distribution of power used exclusively
for operation of rofling stock or installations used
exclusively for signaling and communications purposes

(4) Installations of communications equipment under the
exclusive control of communications utilities located
outdoors or in building spaces used exclusively for
such installations

(5) Installations under the exclusive control of an electric
utility where such installations

a. Consist of service drops or service laterals, and
associated metering, or

b. Are located in legally established easements or
rights-of-way designated by or recognized by
public service commissions, utility commissions,
or other regulatory agencies having jurisdiction
for such installations, or

c. Are on property owned or leased by the electric
utility for the purpose of communications,
metering, generation, control, transformation,
transmission, or distribution of electric energy.

FPN to (4) and (5): Examples of utilities may include those
entities that are typically designated or recognized by
govemmental law or regulation by public service/utility
commissions and that install, operate, and maintain electric
supply (such as generation, transmission, or distribution
systems) or communication systems (such as telephone,
CATV, Intemet, satellite, or data services). Utilities may be
subject to compliance with codes and standards covering their
regulated activities as adopted under govemmental law or
regulation. Additional information can be found through
consultation with the appropriate govemmental bodies, such as
state regulatory commissions, the Federal Energy Regulatory
Commission, and the Federal Communications Commission.

(C) Special Permission. The authority having
jurisdiction for enforcing this Code may grant exception
for the installation of conductors and equipment that are
not under the exclusive control of the electric utilities and
are used to connect the electric utility supply system to
the service-entrance conductors of the premises served,
provided such installations are outside a building or
terminate immediately inside a building wall.

2010 California Electrical Code

70-21

90.3

ARTICLE 90 - INTRODUCTION

90.3 Code Arrangement. This Code is divided into the
introduction and nine chapters, as shown in Figure 90.3.
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and
7 apply to special occupancies, special equipment, or other
special conditions. These latter chapters supplement or
modify the general rules. Chapters 1 through 4 apply
except as amended by Chapters 5, 6, and 7 for the
particular conditions.

Chapter 8 covers communications systems and is not
subject to the requirements of Chapters 1 through 7 except
where the requirements are specifically referenced in Chapter 8.

Chapter 9 consists of tables that are f^pp}%<^M:M
referenced.

Annexes are not part of the requirements of this Code
but are included for informational purposes only.

Chapter 1-» General

Chapter 2 - Wiring and Protection

Chapter 3 - Wiring Methods and Materials

Chapter 4 -^ Equipment for General Use

Applies generally
' to all electrical
installations

Supplaments or modifies ^
Chapters Uhrough 4

Chapter 5 - Special Ocx)upanoies

Chapter 6 -"Special Equipment

Chapter 7 -Special Conditions

Chapter 8 - Communications Systems

Chapter 9 -« Tables

Annex A through Annex H

Chapter 8 is not sut)iect
to the requirements of
Chapters 1 through 7 ax(^pt
'where the requiremente are
speciioally referenced in
Chapters.

-Applicabte as referenced

Jnformationaionly;
not mandatory

Figure 90.3 Code Arrangement.

90.4 Enforcement. This Code is intended to be suitable
for mandatory application by governmental bodies that
exercise legal jurisdiction over electrical installations,
including signaling and communications systems, and for
use by insurance inspectors. The authority having
jurisdiction for enforcement of the Code has the
responsibility for making interpretations of the rules, for
deciding on the approval of equipment and materials, and

for granting the special permission contemplated in a
number of the rules.

By special permission, the authority having
jurisdiction may waive specific requirements in this Code
or permit alternative methods where it is assured that
equivalent objectives can be achieved by establishing and
maintaining effective safety.

This Code may require new products, constructions, or
materials that may not yet be available at the time the Code
is adopted. In such event, the authority having jurisdiction
may permit the use of the products, constructions, or
materials that comply with the most recent previous edition
of this Code adopted by the jurisdiction.

90.5 Mandatory Rules, Permissive Rules, and
Explanatory Material.

(A) Mandatory Rules. Mandatory rules of this Code are
those that identify actions that are specifically required or
prohibited and are characterized by the use of the terms
shall or shall not.

(B) Permissive Rules. Permissive rules of this Code are
those that identify actions that are allowed but not required,
are normally used to describe options or alternative
methods, and are characterized by the use of the terms shall
be permitted or shall not be required,

(C) Explanatory Material. Explanatory material, such as
references to other standards, references to related sections
of this Code, or information related to a Code rule, is
included in this Code in the form of fine print notes
(FPNs). Fine print notes are informational only and are not
enforceable as requirements of this Code.

Brackets containing section references to another NFPA
document are for informational purposes only and are
provided as a guide to indicate the source of the extracted
text. These bracketed references immediately follow the
extracted text.

FPN: The format and language used in this Code follows
guidelines established by NFPA and published in the NEC Style
Manual Copies of this manual can be obtained from NFPA.

90.6 Formal Interpretations. To promote uniformity of
interpretation and application of the provisions of this
Code, formal interpretation procedures have been
established and are found in the NFPA Regulations
Governing Committee Projects.

70-22

2010 California Electrical Code

ARTICLE 90 - INTRODUCTION

90.9

90.7 Examination of Equipment for Safety. For specific
items of equipment and materials referred to in this Code,
examinations for safety made under standard conditions
provide a basis for approval where the record is made
generally available through promulgation by organizations
properly equipped and qualified for experimental testing,
inspections of the run of goods at factories, and service-
value determination through field inspections. This avoids
the necessity for repetition of examinations by different
examiners, frequently with inadequate facilities for such
work, and the confusion that would resuh from conflicting
reports on the suitability of devices and materials examined
for a given purpose.

It is the intent of this Code that factory-installed
internal wiring or the construction of equipment need not
be inspected at the time of installation of the equipment,
except to detect aherations or damage, if the equipment has
been listed by a qualified electrical testing laboratory that is
recognized as having the facilities described in the
preceding paragraph and that requires suitability for
installation in accordance with this Code.

FPN No. 1 : See requirements in 1 10.3.

FPN No. 2: Listed \^ defined in Article 100.

FPN No. 3: Annex A contains an informative list of product
safety standards for electrical equipment.

90.8 Wiring Planning.

(A) Future Expansion and Convenience. Plans and
specifications that provide ample space in raceways, spare
raceways, and additional spaces allow for future increases
in electric power and communication circuits. Distribution
centers located in readily accessible locations provide
convenience and safety of operation.

(B) Number of Circuits in Enclosures. It is elsewhere
provided in this Code that the number of wires and circuits
confined in a single enclosure be varyingly restricted.
Limiting the number of circuits in a single enclosure
minimizes the effects from a short circuit or ground fault in
one circuit.

90.9 Units of Measurement.

(A) Measurement System of Preference. For the purpose
of this Code, metric units of measurement are in
accordance with the modernized metric system known as
the International System of Units (SI).

(B) Dual System of Units, SI units shall appear first, and
inch-pound units shall immediately follow in parentheses.
Conversion from inch-pound units to SI units shall be
based on hard conversion except as provided in 90.9(C).

(C) Permitted Uses of Soft Conversion. The cases given
in 90.9(C)(1) through (C)(4) shall not be required to use
hard conversion and shall be permitted to use soft
conversion.

(1) Trade Sizes. Where the actual measured size of a
product is not the same as the nominal size, trade size
designators shall be used rather than dimensions. Trade
practices shall be followed in all cases.

(2) Extracted Material. Where material is extracted from
another standard, the context of the original material shall
not be compromised or violated. Any editing of the
extracted text shall be confined to making the style
consistent with that of the NEC.

(3) Industry Practice. Where industry practice is to
express units in inch-pound units, the inclusion of SI units
shall not be required.

(4) Safety. Where a negative impact on safety would
result, soft conversion shall be used.

(D) Compliance. Conversion from inch-pound units to SI
units shall be permitted to be an approximate conversion.
Compliance with the numbers shown in either the SI
system or the inch-pound system shall constitute
compliance with this Code.

FPN No. 1: Hard conversion is considered a change in
dimensions or properties of an item into new sizes that
might or might not be interchangeable with the sizes used in
the original measurement. Soft conversion is considered a
direct mathematical conversion and involves a change in the
description of an existing measurement but not in the aclual
dimension.

FPN No. 2: SI conversions are based on lEEE/ASTM SI 10-
1991 , Standard for the Use of the International System of
Units (SI): The Modern Metric System.

2010 California Electrical Code

70-23

CHAPTER 1 CALIFORNIA MATRIX ADOPTION TABLE

•

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.
70-23.1 ■ \ 2010 California Electrical Code

CHAPTER 1 CALIFORNIA MATRIX ADOPTION TABLE

CHAPTER 1 - GENERAL

Adopting Agency

BSC

SFM

HOD

DSA

OSHPD

DPH

ss/cc

Adopt Entire Chapter

Adopt Entire Chapter as amended
(amended sections listed below)

Adopt only those articles / sections
that are listed below

Article / Section

100 / Coordination (Selective)

110.2

110.13(C)

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is apphcable to structures subject to BCD 1 and/or HCD 2.
2010 California Electrical Code 70-23.2

CHAPTER 1

ARTICLE 100 -DEFINITIONS

Chapter 1 General

Definitions

Scope. This article contains only those definitions essential
to the proper application of this Code. It is not intended to
include conimonly defined general terms or commonly
defined technical terms from related codes and standards.
In general, only those terms that are used in two or more
articles are defined in Article 100. Other definitions are
included in the article in which they are used but may be
referenced in Article 100.

Part I of this article contains definitions intended to
apply wherever the terms are used throughout this Code.
Part II contains definitions applicable only to the parts of
articles specifically covering installations and equipment
operating at over 600 volts, nominal.

I. General

Accessible (as applied to equipment). Admitting close
approach; not guarded by locked doors, elevation, or other
effective means.

Accessible (as applied to wiring methods). Capable of
being removed or exposed without damaging the building
structure or finish or not permanently closed in by the
structure or finish of the building.

Accessible, Readily (Readily Accessible). Capable of
being reached quickly for operation, renewal, or
inspections without requiring those to whom ready access
is requisite to climb over or remove obstacles or to resort to
portable ladders, and so forth.

Ampacity. The current, in amperes, that a conductor can
carry continuously under the conditions of use without
exceeding its temperature rating.

Appliance. Utilization equipment, generally other than
industrial, that is normally built in standardized sizes or
types and is installed or connected as a unit to perform one
or more functions such as clothes washing, air
conditioning, food mixing, deep frying, and so forth.

Approved. Acceptable to the authority having jurisdiction.

Askarel. A generic term for a group of nonflammable
synthetic chlorinated hydrocarbons used as electrical
insulating media. Askarels of various compositional types
are used. Under arcing conditions, the gases produced,
while consisting predominantly of noncombustible

hydrogen chloride, can include varying amounts of
combustible gases, depending on the askarel type.

Attachment Plug (Plug Cap) (Plug). A device that, by
insertion in a receptacle, establishes a connection between
the conductors of the attached flexible cord and the
conductors connected permanently to the receptacle.

Authority Having Jurisdiction (AHJ). An organization,
office, or individual responsible for enforcing the
requirements of a code or standard, or for approving
equipment, materials, an installation, or a procedure.

FPN: The phrase "authority having jurisdiction," or its
acronym AHJ, is used in NFPA documents in a broad
manner, since jurisdictions and approval agencies vary, as
do their responsibilities. Where public safety is primary, the
authority having jurisdiction may be a federal, state, local,
or other regional department or individual such as a fire
chief; fire marshal; chief of a fire prevention bureau, labor
department, or health department; building official;
electrical inspector; or others having statutory authority. For
insurance purposes, an insurance inspection department,
rating bureau, or other insurance company representative
may be the authority having jurisdiction. In many
circumstances, the property owner or his or her designated
agent assumes the role of the authority having jurisdiction;
at government installations, the commanding officer or
departmental official may be the authority having
jurisdiction.

Automatic. Self-acting, operating by its own mechanism
when actuated by some impersonal influence, as, for
example, a change in current, pressure, temperature, or
mechanical configuration.

Bathroom. An area including a basin with one or more of
the following: a toilet, a tub, or a shower.

Bonded ; (Bonding).: ponnected to- ^es^tablish ; electf ical
<^ntinuity and coiidttCtiivity|

Bonding Jumper. A reliable conductor to ensure the
required electrical conductivity between metal parts
required to be electrically connected.

Bonding Jumper, Equipment. The cormection between
two or more portions of the equipment grounding
conductor.

Bonding Jumper, Main. The connection between the
grounded circuit conductor and the equipment grounding
conductor at the service.

Branch Circuit. The circuit conductors between the final
overcurrent device protecting the circuit and the outlet(s).

Branch Circuit, Appliance. A branch circuit that supplies
energy to one or more outlets to which apphances are to be
connected and that has no permanently connected
luminaires that are not a part of an appliance.

70-24

2010 California Electrical Code

ARTICLE 100 - DEFINITIONS

CHAPTER 1

Branch Circuit, General-Purpose. A branch circuit that
supplies two or more receptacles or outlets for lighting and
appliances.

Branch Circuit, Individual. A branch circuit that supplies
only one utilization equipment.

Branch Circuit, Multiwire. A branch circuit that consists
of two or more ungrounded conductors that have a voltage
between them, and a grounded conductor that has equal
voltage between it and each ungrounded conductor of the
circuit and that is connected to the neutral or grounded
conductor of the system.

Bmiieh-C^lreiiit Ov^rctt'rre^^ Ajdeyioe ,cl[|)abie of

jaad[eqiuipnietit bvcr the- Mtim^^pJ m^cuttjkxU i^^iwphi,

its^mted current md kimtkmipMg ti^^^

bvf tciip-eit ptot^ctive , deyic^ ' A^^^^' JP^PYided with

Building. A structure that stands alone or that is cut off
from adjoining structures by fire walls with all openings
therein protected by approved fire doors.

Cabinet. An enclosure that is designed for either surface
mounting or flush mounting and is provided with a frame,
mat, or trim in which a swinging door or doors are or can
be hung.

Circuit Breaker. A device designed to open and close a
circuit by nonautomatic means and to open the circuit
automatically on a predetermined overcurrent without
damage to itself when properly appHed within its rating.

FPN: The automatic opening means can be integral, direct acting
with the circuit breaker, or remote from the circuit breaker.

Adjustable (as applied to circuit breakers). A qualifying
term indicating that the circuit breaker can be set to trip at
various values of current, time, or both, within a
predetermined range.

Instantaneous Trip (as applied to circuit breakers). A
qualifying term indicating that no delay is purposely
introduced in the tripping action of the circuit breaker.

Inverse Time (as applied to circuit breakers), A qualifying
term indicating that there is purposely introduced a delay in
the tripping action of the circuit breaker, which delay
decreases as the magnitude of the current increases.

Nonadjustable (as applied to circuit breakers). A
qualifying term indicating that the circuit breaker does not
have any adjustment to alter the value of current at which it
will trip or the time required for its operation.

Setting (of circuit breakers). The value of current, time, or
both, at which an adjustable circuit breaker is set to trip,

jClc»^gS: Clmtt. Amii:^ roor^ or space jotfn4^4

pritti&EY;forstq^

Communications Equipment. The electronic equipment
that performs the telecommunications operations for the
transmission of audio, video, and data, and includes power
equipment (e.g., dc converters, inverters, and batteries) and
technical support equipment (e.g., computers).

Concealed. Rendered inaccessible by the structure or finish
of the building. Wires in concealed raceways are
considered concealed, even though they may become
accessible by withdrawing them.

Conductor, Bare. A conductor having no covering or
electrical insulation whatsoever.

Conductor, Covered. A conductor encased within material
of composition or thickness that is not recognized by this
Code as electrical insulation.

Conductor, Insulated. A conductor encased within
material of composition and thickness that is recognized by
this Code as electrical insulation.

Conduit Body. A separate portion of a conduit or tubing
system that provides access through a removable cover(s)
to the interior of the system at a junction of two or more
sections of the system or at a terminal point of the system.

Boxes such as FS and FD or larger cast or sheet metal
boxes are not classified as conduit bodies.

Connector, Pressure (Solderless). A device that establishes
a connection between two or more conductors or between
one or more conductors and a terminal by means of
mechanical pressure and without the use of solder.

Continuous Load. A load where the maximum current is
expected to continue for 3 hours or more.

Controller. A device or group of devices that serves to
govern, in some predetermined manner, the electric power
delivered to the apparatus to which it is connected.

Cooking Unit, Counter-Mounted. A cooking appliance
designed for mounting in or on a counter and consisting of
one or more heating elements, internal wiring, and built-in
or mountable controls.

Coordination (Selective). Localization of an overcurrent
condition to restrict outages to the circuit or equipment
affected, accomplished by the choice of overcurrent
protective devices and their ratings or settings, [OSHPD 1,
2, 5, & 4] utilizing the 0.10 second level of the overcurrent
protective device from the time current curve as the basis
for the lower limit of the calculation method,

Copper-Clad Aluminum Conductors. Conductors drawn
from a copper-clad aluminum rod with the copper
metallurgically bonded to an aluminum core. The copper
forms a minimum of 10 percent of the cross-sectional area
of a solid conductor or each strand of a stranded conductor.

2010 California Electrical Code

70-25

CHAPTER 1

ARTICLE 100 - DEFINITIONS

Cutout Box. An enclosure designed for surface mounting
that has swinging doors or covers secured directly to and
telescoping with the walls of the box proper.

Dead Front. Without live parts exposed to a person on the
operating side of the equipment.

Demand Factor. The ratio of the maximum demand of a
system, or part of a system, to the total connected load of a
system or the part of the system under consideration.

Device. A unit of an electrical system that bames, or
controls electric energy as its principal feriction.

Disconnecting Means. A device, or group of devices, or
other means by which the conductors of a circuit can be
disconnected from their source of supply.

Dusttight. Constructed so that dust will not enter the
enclosing case under specified test conditions.

Duty, Continuous. Operation at a substantially constant
load for an indefinitely long time.

Duty, Intermittent. Operation for altemate intervals of (1) load
and no load; or (2) load and rest; or (3) load, no load, and rest.

Duty, Periodic. Intermittent operation in which the load
conditions are regularly recurrent.

Duty, Short-Time. Operation at a substantially constant
load for a short and definite, specified time.

Duty, Varying. Operation at loads, and for intervals of
time, both of which may be subject to wide variation.

Dwelling, One-Family. A building that consists solely of
one dwelling unit.

Dwelling, Two-Family. A building that consists solely of
two dwelling units.

Dwelling, Multifamily. A building that contains three or
more dwelling units.

Dwelling Unit. A single unit, providing complete and
independent Hving facilities for one or more persons,
including permanent provisions for living, sleeping,
cooking, and sanitation.

Electric Sign. A fixed, stationary, or portable self-
contained, electrically illuminated utilization equipment
with words or symbols, designed to convey information or
attract attention.

■ ?9ii?M^^ont]K^M^

Enclosed. Surrounded by a case, housing, fence, or wall(s)
that prevents persons from accidentally contacting
energized parts.

Enclosure. The case or housing of apparatus, or the fence
or walls surrounding an installation to prevent personnel
from accidentally contacting energized parts or to protect
the equipment from physical damage.

FPN: ^^eTabfe IJO.^ for examples of enclosure types.

Energized. Electrically connected to, or is, a source of
voltage.

Equipment. A general term, including material, fittings,
devices, appliances, luminaires, apparatus, m^cMj^ry; and
the like used as a part of, or in connection with, an
electrical installation.

Explosionproof Apparatus. Apparatus enclosed in a case that
is capable of withstanding an explosion of a specified gas or
vapor that may occur within it and of preventing the ignition of
a specified gas or vapor surrounding the enclosure by sparks,
flashes, or explosion of the gas or vapor within, and that
operates at such an external temperature that a surrounding
flammable atmosphere will not be ignited thereby.

FPN: For fiirther information, see ANSI/UL 1203-1999,
Explosion-Proof and Dust-Ignition-Proof Electrical
Equipment for Use in Hazardous (Classified) Locations.

Exposed (as applied to live parts). Capable of being
inadvertently touched or approached nearer than a safe
distance by a person. It is applied to parts that are not
suitably guarded, isolated, or insulated.

Exposed (as appHed to wiring methods). On or attached to
the surface or behind panels designed to allow access.

Externally Operable. Capable of being operated without
exposing the operator to contact with live parts.

Feeder. All circuit conductors between the service
equipment, the source of a separately derived system, or
other power supply source and the final branch-circuit
overcurrent device.

Festoon Lighting. A string of outdoor lights that is
suspended between two points.

Fitting. An accessory such as a locknut, bushing, or other
part of a wiring system that is intended primarily to
perform a mechanical rather than an electrical fiinction.

Garage. A building or portion of a building in which one
or more self-propelled vehicles can be kept for use, sale,
storage, rental, repair, exhibition, or demonstration purposes.

FPN: For commercial garages, repair and storage, see
Article 511.

Ground. ^fefeartKj

Grounded iGrmm^ng)] Connected (connecting) to
ground or to a conductive body that e^tgaids f^^^^

Isi^iytioiiii

70-26

2010 California Electrical Code

ARTICLE 100 - DEFINITIONS

CHAPTER 1

Grounded, Solidly. Connected to ground without inserting
any resistor or impedance device.

Grounded Conductor. A system or circuit conductor that
is intentionally grounded.

Ground-Fault Circuit Interrupter (GFCI). A device
intended for the protection of personnel that functions to
de-energize a circuit or portion thereof within an
established period of time when a current to ground
exceeds the values established for a Class A device.

FPN: Class A ground- fault circuit interrupters trip when the
current to ground i$;_|_mA or h%her'agd'^d^;not;5^^^
Iflie ejjirreilt to groujad is fes^ thaii 4 mSj For further
information, see UL 943, Standard for Ground-Fault
Circuit Interrupters.

Ground-Fault Protection of Equipment. A system intended
to provide protection of equipment from damaging line-to-
ground fault currents by operating to cause a disconnecting
means to open all ungrounded conductors of the fauhed
circuit. This protection is provided at current levels less than
those required to protect conductors from damage through the
operation of a supply circuit overcurrent device.

Grounding Conductor. A conductor used to connect
equipment or the grounded circuit of a wiring system to a
grounding electrode or electrodes.

Grounding Conductor, Equipment ^GG|. The gotldpaSvi

^ffijg^i|te| to connect Sapmi^R non-current-carrying metal
parts of equipment pOj ^ief m ^ to the system grounded
conductor or to the grounding electrode conductor, pr bolh.

ijptAJ^Mr^a fe ,p etfonn^.bSn,togJ

SfM.ift 2: 'See^ 2S0;-i I t,"fot i tet Wja^j^^He^^^^

gqpJittactoEs^
Grounding Electrode, Ik cqBjacffi|^^^^^

Grounding Electrode Conductor^ ^ eoBdiactor ^s^jy
j^nnect Ae: system grbuided eoiidiictor or the ^^^ymmmi tB,

Guarded. Covered, shielded, fenced, enclosed, or
otherwise protected by means of suitable covers, casings,
barriers, rails, screens, mats, or platforms to remove the
likelihood of approach or contact by persons or objects to a
point of danger.

Guest Room. An accommodation combining living,
sleeping, sanitary, and storage facilities within a
compartment.

Guest Suite. An accommodation with two or more
contiguous rooms comprising a compartment, with or
without doors between such rooms, that provides living,
sleeping, sanitary, and storage facilities.

Handhole Enclosure, An enclosure for use in underground
systems, provided with an open or closed bottom, and sized
to allow personnel to reach into, but not enter, for the
purpose of installing, operating, or maintaining equipment
or wiring or both.

Hoistway. Any shaflway, hatchway, well hole, or other
vertical opening or space in which an elevator or
dumbwaiter is designed to operate.

Identified (as applied to equipment). Recognizable as
suitable for the specific purpose, function, use,
environment, application, and so forth, where described in
a particular Code requirement.

FPN: Some examples of ways to determine suitability of
equipment for a specific purpose, environment, or
appHcation include investigations by a qualified testing
laboratory (listing and labeling), an inspection agency, or
other organizations concemed with product evaluation.

In Sight From (Within Sight From, Within Sight). Where
this Code specifies that one equipment shall be "in sight
from," "within sight from," or "within sight of," and so forth,
another equipment, the specified equipment is to be visible
and not more than 1 5 m (50 ft) distant from the other.

Interactive System. An electric power production system
that is operating in parallel with and capable of delivering
energy to an electric primary source supply system.

Interrupting Rating. The highest current at rated voltage that
a device is intended to interrupt under standard test conditions.

FPN: Equipment intended to interrupt current at other than
fault levels may have its interrupting rating implied in other
ratings, such as horsepower or locked rotor current.

^ovMjss ame^ans^for conEe<^|g comBjwcations systeS(s)
groundilxg mndmtpi^d) and bpndiiig conductor{s) at tto
keryice equipment or _ ^ ^J^q Am^^ „.8l^^^ „ fo|

ftmldings/or ^^ktoctures^, §t^^ byj;"a_'Jeedet,'orJ;fe
bircuiti

Isolated (as applied to location). Not readily accessible to
persons unless special means for access are used.

Kilclieri^ Ail' ar^a with a^sffik and penMnent facjlilies for
ifoodpcejjaratioi^^

Labeled. Equipment or materials to which has been
attached a label, symbol, or other identifying mark of an
organization that is acceptable to the authority having
jurisdiction and concemed with product evaluation, that

2010 California Electrical Code

70-27

CHAPTER 1

ARTICLE 100 - DEFINITIONS

maintains periodic inspection of production of labeled
equipment or materials, and by whose labeling the
manufacturer indicates compliance with appropriate
standards or performance in a specified manner.

Lighting Outlet, An outlet intended for the direct
connection of a lampholder or luminaire.

Listed. Equipment, materials, or services included in a list
published by an organization that is acceptable to the authority
having jurisdiction and concerned with evaluation of products
or services, that maintains periodic inspection of production of
listed equipment or materials or periodic evaluation of
services, and whose listing states that either the equipment,
material, or service meets appropriate designated standards or
has been tested and found suitable for a specified purpose.

FPN: The means for identifying listed equipment may vary
for each organization concemed with product evaluation,
some of which do not recognize equipment as listed unless
it is also labeled. Use of the system employed by the listing
organization allows the authority having jurisdiction to
identify a listed product.

Live Parts. Energized conductive components.

Location, Damp. Locations protected from weather and
not subject to saturation with water or other liquids but
subject to moderate degrees of moisture. Examples of such
locations include partially protected locations under
canopies, marquees, roofed open porches, and like
locations, and interior locations subject to moderate
degrees of moisture, such is some basements, some bams,
and some cold-storage warehouses.

Location, Dry. A location not normally subject to
danipness or wetness. A location classified as dry may be
temporarily subject to dampness or wetness, as in the case
of a building under construction.

Locatioii, Wet. Installations underground or in concrete
slabs or masonry in direct contact with the earth; in
locations subject to saturation with water or other liquids,
such as vehicle washing areas; and in unprotected locations
exposed to weather.

Luminaire. 'A;MJ^^^!:ltm^:^WM:

10 gmitibftfte ^smm'^^^j^j^'^^'^ %i^'p*??^.^^%f, ^

Metal-Enclosed Power Switchgear. A switchgear
assembly completely enclosed on all sides and top with
sheet metal (except for ventilating openings and inspection
windows) and containing primary power circuit switching,
interrupting devices, or both, with buses and connections.
The assembly may include control and auxiliary devices.

Access to the interior of the enclosure is provided by doors,
removable covers, or both. Mpt£h^mlq^J/jpqw
^^t^g_^^w^^^^

Motor Control Center. An assembly of one or more
enclosed sections having a conomon power bus and
principally containing motor control units.
Multioutlet Assembly. A type of surface, flush, or
freestanding raceway designed to hold conductors and
receptacles, assembled in the field or at the factory.

dgfa;sysiein,^ot4ffl#^tetl';3^
b| ;,§|'iJiSi%^ '§om W^^

'^M^lsmrq: potoiWlil
Nonautomatic. Action requiring personal intervention for
its control. As applied to an electric controller,
nonautomatic control does not necessarily imply a manual
controller, but only that personal intervention is necessary.
Nonlinear Load. A load where the wave shape of the
steady-state current does not follow the wave shape of the
applied voltage.

FPN: Electronic equipment, electronic/electric-discharge

lighting, adjustable-speed drive systems, and similar

equipment may be nonlinear loads.

Outlet. A point on the wiring system at which current is
taken to supply utilization equipment.

Outline Lighting. An arrangement of incandescent lamps,
electric-discharge lighting, or other electrically powered light
sources to outline or call attention to certain features such as
the shape of a building or the decoration of a window.

Overcurrent. Any current in excess of the rated current of
equipment or the ampacity of a conductor. It may result
from overload, short circuit, or ground fault.

FPN: A current in excess of rating may be accommodated
by certain equipment and conductors for a given set of
conditions. Therefore, the rules for overcurrent protection
are specific for particular situations.

Overload. Operation of equipment in excess of normal,
full-load rating, or of a conductor in excess of rated ampacity
that, when it persists for a sufficient length of time, would
cause damage or dangerous overheating. A fault, such as a
short circuit or ground fault, is not an overload.

70-28

2010 California Electrical Code

ARTICLE 100 - DEFINITIONS

CHAPTER 1

Panelboard. A single panel or group of panel units
designed for assembly in the form of a single panel,
including buses and automatic overcurrent devices, and
equipped with or without switches for the control of light,
heat, or power circuits; designed to be placed in a cabinet
or cutout box placed in or against a wall, partition, or other
support; and accessible only from the front.

Plenum. A compartment or chamber to which one or more
air ducts are connected and that forms part of the air
distribution system.

Power Outlet. An enclosed assembly that may include
receptacles, circuit breakers, fiiseholders, fused switches,
buses, and watt-hour meter mounting means; intended to
supply and control power to mobile homes, recreational
vehicles, park trailers, or boats or to serve as a means for
distributing power required to operate mobile or
temporarily installed equipment.

Premises Wiring (System). Interior and exterior wiring,
including power, lighting, control, and signal circuit wiring
together with all their associated hardware, fittings, and
wiring devices, both permanently and temporarily installed.

^oujccert^!!tfte outfets or ft) wiring Mmjm^ iBcliidtafi'tfi^.

Such wiring does not include wiring internal to
appliances, luminaires, motors, controllers, motor control
centers, and similar equipment.

Qualified Person. One who has skills and knowledge
related to the construction and operation of the electrical
equipment and installations and has received safety training
|^r&o§ii?e^a §y<33 the hazards involved.

FPN: Refer to NFPA 70E®-2004, Standard for Electrical
Safety in the Workplace, for electrical safety training
requirements.

Raceway. An enclosed channel of metal or nonmetallic
materials designed expressly for holding wires, cables, or
busbars, with additional functions as permitted in this
Code. Raceways include, but are not limited to, rigid metal
conduit, rigid nonmetallic conduit, intermediate metal
conduit, liquidtight flexible conduit, flexible metallic
tubing, flexible metal conduit, electrical nonmetallic
tubing, electrical metallic tubing, underfloor raceways,
cellular concrete floor raceways, cellular metal floor
raceways, surface raceways, wireways, and busways.

Rainproof. Constructed, protected, or treated so as to
prevent rain from interfering with the successful operation
of the apparatus under specified test conditions.

Raintight. Constructed or protected so that exposure to a
beating rain will not result in the entrance of water under
specified test conditions.

Receptacle. A receptacle is a contact device installed at the
outlet for the connection of an attachment plug. A single
receptacle is a single contact device with no other contact
device on the same yoke. A multiple receptacle is two or
more contact devices on the same yoke.

Receptacle Outlet. An outlet where one or more
receptacles are installed.

Remote-Control Circuit. Any electrical circuit that
controls any other circuit through a relay or an equivalent
device.

Sealable Equipment. Equipment enclosed in a case or
cabinet that is provided with a means of sealing or locking
so that live parts cannot be made accessible without
opening the enclosure. The equipment may or may not be
operable without opening the enclosure.

Separately Derived System. A premises wiring system
whose power is derived from a source of electric energy or
equipment other than a service. Such systems have no
direct electrical connection, including a solidly connected
grounded circuit conductor, to supply conductors
originating in another system.

Service. The conductors and equipment for delivering
electric energy from the serving utility to the wiring system
of the premises served.

Service Cable. Service conductors made up in the form of
a cable.

Service Conductors. The conductors from the service
point to the service disconnecting means.

Service Drop. The overhead service conductors from the
last pole or other aerial support to and including the splices,
if any, connecting to the service-entrance conductors at the
building or other structure.

Service-Entrance Conductors, Overhead System. The

service conductors between the terminals of the service
equipment and a point usually outside the building, clear of
building walls, where joined by tap or splice to the service drop.

Service-Entrance Conductors, Underground System.

The service conductors between the terminals of the service
equipment and the point of connection to the service lateral.

FPN: Where service equipment is located outside the
building walls, there may be no service-entrance conductors
or they may be entirely outside the building.

Service Equipment. The necessary equipment, usually
consisting of a circuit breaker(s) or switch(es) and fuse(s)
and their accessories, connected to the load end of service
conductors to a building or other structure, or an otherwise
designated area, and intended to constitute the main control
and cutoff of the supply.

2010 California Electrical Code

70-29

CHAPTER 1

ARTICLE 100 -DEFINITIONS

Service Lateral. The underground service conductors
between the street main, including any risers at a pole or
other structure or from transformers, and the first point of
connection to the service -entrance conductors in a terminal
box or meter or other enclosure, inside or outside the
building wall. Where there is no terminal box, meter, or
other enclosure, the point of connection is considered to be
the point of entrance of the service conductors into the
building.

Service Point, The point of connection between the
facilities of the serving utility and the premises wiring.

Short-Circuit ^ Current _^_^RaBiig._^_T^^ j^rostpectiyd

jsymmetrical fault curreat at a nominal voltage to ^ich an
apparatus or systern is abie tg Idc cqmecte^^^^
sustaining damage exceeding denned acceptance ctiteriaJ

Show Window. Any window used or designed to be used
for the display of goods or advertising material, whether it
is fully or partly enclosed or entirely open at the rear and
whether or not it has a platform raised higher than the street
floor level.

Signaling Circuit. Any electrical circuit that energizes
signaling equipment.

Solar Photovoltaic System. The total components and
subsystems that, in combination, convert solar energy into
electric energy suitable for connection to a utilization load.

Special Permission. The written consent of the authority
having jurisdiction.

Structure. That which is built or constructed.

Supplementary Overcurrent Protective Device. A device
intended to provide limited overcurrent protection for
specific applications and utilization equipment such as
luminaires and appliances. This limited protection is in
addition to the protection provided in the required branch
circuit by the branch circuit overcurrent protective device.

Surge Arrester* A prqtecSve device fo^
voltages by discharging or bypassing surge current; it also
l>revents continued flow of follow current wMlerema^^^^
capable of repeating tiiese functions.;

Surge-Protective Device (SPD)* A protective device fot
limiting transient voltages by divertmg or limiting sur^^
current; it also prevents continued flow of follow cnrrenti
while remaining capable of repeating these fimctions and J^
designated as follows:

Type 1: Permanently connected SPDs intended Jd
installation between the secondary of the service;
transformer and the line side of the service disconnect
overcurrent device.

Ty;^p^J.l^^QtmmtM^ jntended |ot

installatiotL,i?^. , ii^ ^^M^j}^.,^^, '^^APV^i^^ ''Ay?^99V^^i

bvercun:e^t_ deyice,^ inc|udiag^SPD^§ Jocate^ tli?.bl^[^K

panel;

Type 3: Point of ftlFzationSPDs]

„ _ £??? "- i*.-~~,!?^W^Mi-^SIS-^ ..5^^lldmg^_ discrete!
bpinponentSj as well as IssemWiesJ

FFN:',Fpr Slither infopnatiqfi;on Typ^, ,1, T>^e 2,; Type 3J

'Protective Devices.

Switch, Bypass Isolation. A manually operated device
used in conjunction with a transfer switch to provide a
means of directly connecting load conductors to a power
source and of disconnecting the transfer switch.

Switch, General-Use. A switch intended for use in
general distribution and branch circuits. It is rated in
amperes, and it is capable of interrupting its rated current at
its rated voltage.

Switch, General-Use Snap. A form of general-use switch
constructed so that it can be installed in device boxes or on
box covers, or otherwise used in conjunction with wiring
systems recognized by this Code.

Switch, Isolating. A switch intended for isolating an
electrical circuit from the source of power. It has no
interrupting rating, and it is intended to be operated only
after the circuit has been opened by some other means.

Switch, Motor-Circuit. A switch rated in horsepower that
is capable of interrupting the maximum operating overload
current of a motor of the same horsepower rating as the
switch at the rated voltage.

Switch, Transfer. An automatic or nonautomatic device
for transferring one or more load conductor connections
from one power source to another.

Switchboard. A large single panel, frame, or assembly of
panels on which are mounted on the face, back, or both,
switches, overcurrent and other protective devices, buses,
and usually instruments. Switchboards are generally
accessible from the rear as well as from the front and are
not intended to be installed in cabinets.

Thermally Protected (as applied to motors). The words
Thermally Protected appearing on the nameplate of a motor
or motor-compressor indicate that the motor is provided
with a thermal protector.

Thermal Protector (as applied to motors). A protective
device for assembly as an integral part of a motor or motor-
compressor that, when properly applied, protects the motor
against dangerous overheating due to overload and failure
to start.

•

70-30

2010 California Electrical Code

ARTICLE 100 - DEFINITIONS

CHAPTER 1

FPN: The thermal protector may consist of one or more
sensing elements integral with the motor or motor-
compressor and an external control device.

jbo&y thai :€^xtettds tlie p'oimd cbm^otioil

^ki^^^ehyerpoyimttQ the utilityJ

Utilization Equipment. Equipment that utilizes electric
energy for electronic, electromechanical, chemical, heating,
lighting, or similar purposes.

Ventilated. Provided with a means to permit circulation of
air sufficient to remove an excess of heat, fumes, or vapors.

Volatile Flammable Liquid. A flammable liquid having a
flash point below 38°C (100°F), or a flammable liquid
whose temperature is above its flash point, or a Class II
combustible liquid that has a vapor pressure not exceeding
276 kPa (40 psia) at 38°C (100°F) and whose temperature
is above its flash point.

Voltage (of a circuit). The greatest root-mean-square
(rms) (effective) difference of potential between any two
conductors of the circuit concerned.

FPN: Some systems, such as 3 -phase 4-wire, single-phase
3-wire, and 3 -wire direct current, may have various circuits
of various voltages.

Voltage, Nominal. A nominal value assigned to a circuit
or system for the purpose of conveniently designating its
voltage class (e.g., 120/240 volts, 480Y/277 volts, 600
volts). The actual voltage at which a circuit operates can
vary from the nominal within a range that permits
satisfactory operation of equipment.

FPN: See ANSI C84. 1-2006, Voltage Ratings for Electric
Power Systems and Equipment (60 Hz),

Voltage to Ground. For grounded circuits, the voltage
between the given conductor and that point or conductor of
the circuit that is grounded; for ungrounded circuits, the
greatest voltage between the given conductor and any other
conductor of the circuit.

Watertight. Constructed so that moisture will not enter
the enclosure under specified test conditions.

Weatherproof. Constructed or protected so that exposure
to the weather will not interfere with successful operation.

FPN: Rainproof, raintight, or watertight equipment can
fulfill the requirements for weatherproof where varying
weather conditions other than wetness, such as snow, ice,
dust, or temperature extremes, are not a factor.

II. Over 600 Volts, Nominal

Whereas the preceding definitions are intended to apply
wherever the terms are used throughout this Code, the
following definitions are applicable only to parts of the
article specifically covering installations and equipment
operating at over 600 volts, nominal.

Electronically Actuated Fuse, An overcurrent protective
device that generally consists of a control module that
provides current sensing, electronically derived time-
current characteristics, energy to initiate tripping, and an
interrupting module that interrupts current when an
overcurrent occurs. Electronically actuated fuses may or
may not operate in a current-limiting fashion, depending on
the type of control selected.

Fuse. An overcurrent protective device with a circuit-
opening fusible part that is heated and severed by the
passage of overcurrent through it.

FPN: A fuse comprises all the parts that form a unit capable
of performing the prescribed functions. It may or may not
be the complete device necessary to connect it into an
electrical circuit.

Controlled Vented Power Fuse. A fuse with provision for
controlling discharge circuit interruption such that no solid
material may be exhausted into the surrounding atmosphere.

FPN: The fiise is designed so that discharged gases will not
ignite or damage insulation in the path of the discharge or
propagate a flashover to or between grounded members or
conduction members in the path of the discharge where the
distance between the vent and such insulation or conduction
members conforms to manufacturer's recommendations.

Expulsion Fuse Unit (Expulsion Fuse). A vented fuse unit
in which the expulsion effect of gases produced by the arc
and lining of the fuseholder, either alone or aided by a
spring, extinguishes the arc.

Nonvented Power Fuse. A fuse without intentional
provision for the escape of arc gases, liquids, or solid
particles to the atmosphere during circuit interruption.

Power Fuse Unit. A vented, nonvented, or controlled
vented fuse unit in which the arc is extinguished by being
drawn through solid material, granular material, or liquid,
either alone or aided by a spring.

Vented Power Fuse. A fuse with provision for the escape of
arc gases, liquids, or solid particles to the surrounding
atmosphere during circuit interruption.

2010 California Electrical Code

70-31

110.1

ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

Multiple Fuse. An assembly of two or more single-pole

fuses.

Switching Device. A device designed to close, open, or
both, one or more electrical circuits.

Circuit Breaker, A switching device capable of making,
carrying, and interrupting currents under normal circuit
conditions, and also of making, carrying for a specified time,
and interrupting currents under specified abnormal circuit
conditions, such as those of short circuit.

Cutout. An assembly of a fuse support with either a
fuseholder, fuse carrier, or disconnecting blade. The
fUseholder or fuse carrier may include a conducting element
(fuse link) or may act as the disconnecting blade by the
inclusion of a nonfusible member.

Disconnecting Means. A device, group of devices, or other
means whereby the conductors of a circuit can be
disconnected from their source of supply.

Disconnecting (or Isolating) Switch (Disconnector, Isolator),
A mechanical switching device used for isolating a circuit or
equipment from a source of power.

Interrupter Switch. A switch capable of making, carrying,
and interrupting specified currents.

Oil Cutout (Oil-Filled Cutout). A cutout in which all or part
of the fuse support and its fuse link or disconnecting blade is
mounted in oil with complete immersion of the contacts and
the fusible portion of the conducting element (fuse link) so
that arc interruption by severing of the fuse link or by
opening of the contacts will occur under oil.

Oil Switch. A switch having contacts that operate under oil
(or askarel or other suitable liquid).

Regulator Bypass Switch. A specific device or combination
of devices designed to bypass a regulator.

Requireiiieii4^$ for pectrical ItistaUatioiis

I. General

11 0.1 Scope. This article covers general requirements for
the examination and approval, installation and use, access
to and spaces about electrical conductors and equipment;
enclosures intended for personnel entry; and tunnel
installations.

110.2 Approval. The conductors and equipment required or
permitted by this Code shall be acceptable only if approved.

C [OSHPD 1, 2, 3 dt 4] Equipment shall be approvable if it is
A listed, labeled or certified for its use by a Nationally
C Recognized Testing Laboratory (NRTL) as recognized by the

U.S. Department of Labor, Occupational Safety and Health
Administration.

FPN: See 90.7, Examination of Equipment for Safety, and
110.3, Examination, Identification, Installation, and Use of
Equipment. See definitions of Approved, Identified, Labeled,
and Listed.

110.3 Examination, Identification, Installation, and Use
of Equipment

(A) Examination. In judging equipment, considerations
such as the following shall be evaluated:

(1) Suitability for installation and use in conformity with the
provisions of this Code

FPN: Suitability of equipment use may be identified by a
description marked on or provided with a product to identify
the suitability of the product for a specific purpose,
environment, or application. Suitability of equipment may be
evidenced by listing or labeling.

(2) Mechanical strength and durability, including, for parts

designed to enclose and protect other equipment, the
adequacy of the protection thus provided

(3) Wire-bending and connection space

(4) Electrical insulation

(5) Heating effects under normal conditions of use and also
under abnormal conditions likely to arise in service

(6) Arcing effects

(7) Classification by type, size, voltage, current capacity, and

specific use

(8) Other factors that contribute to the practical safeguarding

of persons using or likely to come in contact with the
equipment

(B) Installation and Use. Listed or labeled equipment shall be

installed and used in accordance with any instructions
included in the hsting or labeling.

110.4 Voltages. Throughout this Code, the voltage
considered shall be that at which the circuit operates. The
voltage rating of electrical equipment shall not be less than the
nominal voltage of a circuit to which it is connected.

110.5 Conductors. Conductors normally used to carry
current shall be of copper unless otherwise provided in this
Code. Where the conductor material is not specified, the
material and the sizes given in this Code shall apply to copper
conductors. Where other materials are used, the size shall be
changed accordingly.

FPN: For aluminum and copper-clad aluminum conductors, see
310.15.

110.6 Conductor Sizes. Conductor sizes are expressed in
American Wire Gage (AWG) or in circular mils.

110.7 Wtefiif Integrity. Completed wiring installations shall be

G
A

70-32

2010 California Electrical Code

ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

110.14

free from short circuits, grogSl^jfeS^^

110.8 Wiring Methods. Only wiring methods recognized as
suitable are included in this Code. The recognized methods of
wiring shall be permitted to be installed in any type of
building or occupancy, except as otherwise provided in this
Code.

110.9 Interrupting Rating. Equipment intended to interrupt
current at fault levels shall have an interrupting rating
sufficient for the nominal circuit voltage and the current that is
available at the line terminals of the equipment.

Equipment intended to interrupt current at other than fault
levels shall have an interrupting rating at nominal circuit
voltage sufficient for the current that must be interrupted.

110.10 Circuit Impedance and Other Characteristics. The

overcurrent protective devices, the total impedance, the
component short-circuit current ratings, and other
characteristics of the circuit to be protected shall be selected
and coordinated to permit the circuit-protective devices used
to clear a fauh to do so without extensive damage to the
electrical components of the circuit. This fault shall be
assumed to be either between two or more of the circuit
conductors or between any circuit conductor and the
grounding conductor or enclosing metal raceway. Listed
products applied in accordance with their listing shall be
considered to meet the requirements of this section.

110.11 Deteriorating Agents. Unless identified for use in the
operating environment, no conductors or equipment shall be
located in damp or wet locations; where exposed to gases,
fiimes, vapors, liquids, or other agents that have a deteriorating
effect on the conductors or equipment; or where exposed to
excessive temperatures.

FPN No. 1 ; See 300.6 for protection against corrosion.

FPN No. 2: Some cleaning and lubricating compounds can
cause severe deterioration of many plastic materials used for
insulating and structural applications in equipment.

Eqxaipment bot identified for oiit4obru>e^a^^

idimM^^i&y !& indop^^ iise,; sucfi a$;"te h^9^^'L''3^<>M

^^]QA^M&tAh shall be protected against permanent damage
firom the weather during building construction.

FPN: Accepted industry practices are described in
ANSI/NECA l#06i', Standard Practices for Good
Workmanship in Electrical Contracting, and other ANSI-
approved installation standards.

(A) Unused Openings. Unused op^M^j ote

totetided fot the bpemticm of ^Uipmepj fli^^ fox

'^^^X.^^^¥^M!^^ shall be closed to afford protection
substantially equivalent to the wall of the equipment. Where
metallic plugs or plates are used with nonmetallic enclosures,
they shall be recessed at least 6 mm (Va in.) from the outer
surface of the enclosure.

(B) Integrity of Electrical Equipment and Connections.

Internal parts of electrical equipment, including busbars,
wiring terminals, insulators, and other surfaces, shall not be
damaged or contaminated by foreign materials such as paint,
plaster, cleaners, abrasives, or corrosive residues. There shall
be no damaged parts that may adversely affect safe operation
or mechanical strength of the equipment such as parts that are
broken; bent; cut; or/ deteriorated by corrosion, chemical
action, or overheating.

110.13 Mounting and Cooling of Equipment.

(A) Mounting. Electrical equipment shall be frnnly secured to
the surface on which it is mounted. Wooden plugs driven into
holes in masonry, concrete, plaster, or similar materials shall
not be used.

(B) Cooling. Electrical equipment that depends on the natural
circulation of air and convection principles for cooling of
exposed surfaces shall be installed so that room airflow over
such surfaces is not prevented by walls or by adjacent installed
equipment. For equipment designed for floor mounting,
clearance between top surfaces and adjacent surfaces shall be
provided to dissipate rising warm air.

Electrical equipment provided with ventilating openings
shall be installed so that walls or other obstructions do not
prevent the free circulation of air through the equipment.

shall be anchored and braced to withstand the lateral

110.12 Mechanical Execution of Work. Electrical
equipment shall be installed in a neat and workmanlike
manner.

forces, and shall accommodate calculated displacements as q
required by Part 2, Title 24, C CR. A

110.14 Electrical Connections. Because of different
characteristics of dissimilar metals, devices such as pressure
terminal or pressure splicing connectors and soldering lugs
shall be identified for the material of the conductor and shall
be properly installed and used. Conductors of dissimilar

2010 California Electrical Code

70-33

110.15

ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

metals shall not be intermixed in a terminal or splicing
connector where physical contact occurs between dissimilar
conductors (such as copper and aluminum, copper and
copper-clad aluminum, or aluminum and copper-clad
aluminum), unless the device is identified for the purpose
and conditions of use. Materials such as solder, fluxes,
inhibitors, and compounds, where employed, shall be
suitable for the use and shall be of a type that will not
adversely affect the conductors, installation, or equipment.

FPN: Many terminations and equipment are marked with a

tightening torque.

(A) Terminals. Connection of conductors to terminal parts shall
ensure a thoroughly good connection without damaging the
conductors and shall be made by means of pressure connectors
(including set-screw type), solder lugs, or splices to flexible
leads. Connection by means of wire-binding screws or studs and
nuts that have upturned lugs or the equivalent shall be permitted
for 10 AWG or smaller conductors.

Terminals for more than one conductor and terminals used
to connect aluminum shall be so identified.

(B) Splices. Conductors shall be spliced or joined with splicing
devices identified for the use or by brazing, welding, or
soldering with a fiisible metal or alloy. Soldered splices shall
first be spliced or joined so as to be mechanically and
electrically secure without solder and then be soldered. Ail
spUces and joints and the free ends of conductors shall be
covered with an insulation equivalent to that of the conductors
or with an insulating device identified for the purpose.

Wire connectors or splicing means installed on conductors
for direct burial shall be hsted for such use.

(C) Temperature Limitations. The temperature rating
associated with the ampacity of a conductor shall be selected
and coordinated so as not to exceed the lowest temperature
rating of any connected termination, conductor, or device.
Conductors with temperature ratings higher than specified for
terminations shall be permitted to be used for ampacity
adjustment, correction, or both.

(1) Equipment Provisions. The determination of termination
provisions of equipment shall be based on 110.14(C)(1)(a) or
(C)(1)(b). Unless the equipment is listed and marked otherwise,
conductor ampacities used in determining equipment
termination provisions shall be based on Table 310.16 as
appropriately modified by 3 1 0. 1 5(B)(6).

(a) Termination provisions of equipment for circuits rated
100 amperes or less, or marked for 14 AWG through 1 AWG
conductors, shall be used only for one of the following:

(1) Conductors rated 60°C(140°F).

(2) Conductors with higher temperature ratings, provided the

ampacity of such conductors is determined based on the
60°C (140°F) ampacity of the conductor size used.

(3) Conductors with higher temperature ratings if the equipment

is listed and identified for use with such conductors.

(4) For motors marked with design letters B, C, or D,
conductors having an insulation rating of 75°C (167°F)
or higher shall be permitted to be used, provided the
ampacity of such conductors does not exceed the 75'^C
(167°F) ampacity.

(b) Termination provisions of equipment for circuits
rated over 100 amperes, or marked for conductors larger
than 1 AWG, shall be used only for one of the following:

(1) Conductors rated 75 °C (167°F)

(2) Conductors with higher temperature ratings, provided
the ampacity of such conductors does not exceed the
75°C (167°F) ampacity of the conductor size used, or
up to their ampacity if the equipment is listed and
identified for use with such conductors

(2) Separate Connector Provisions. Separately installed
pressure connectors shall be used with conductors at the
ampacities not exceeding the ampacity at the listed and
identified temperature rating of the connector.

FPN: With respect to 110.14(C)(1) and (C)(2), equipment
markings or listing information may additionally restrict the
sizing and temperature ratings of connected conductors.

110.15 Higii-Leg Marking. On a 4-wire, delta-connected
system where the midpoint of one phase winding is
grounded, only the conductor or busbar having the higher
phase voltage to ground shall be durably and permanently
marked by an outer finish that is orange in color or by other
effective means. Such identification shall be placed at each
point on the system where a connection is made if the
grounded conductor is also present.

110.16 Flash Protection. EleclMcal equipment
switchboards, panelboards, industrial control panels, meter
socket enclosures, and motor control centers, that are in
other than dwelling occupancies, and are likely to require
examination, adjustment, servicing, or maintenance while
energized shall be field marked to warn qualified persons
of potential electric arc flash hazards. The marking shall be
located so as to be clearly visible to qualified persons
before examination, adjustment, servicing, or maintenance
of the equipment.

FPN No. 1 : NFPA 70E-2004, Standard for Electrical Safety
in the Workplace, provides assistance in determining
severity of potential exposure, planning safe work practices,
and selecting personal protective equipment.

FPN No. 2: ANSI Z535.4-1998, Product Safety Signs and
Labels, provides guidelines for the design of safety signs
and labels for application to products.

110.18 Arcing Parts. Parts of electrical equipment that in
ordinary operation produce arcs, sparks, flames, or molten
metal shall be enclosed or separated and isolated from all
combustible material.

FPN: For hazardous (classified) locations, see Articles 500
through 517. For motors, see 430.14.

110.19 Liglit and Power from Railway Conductors.

Circuits for lighting and power shall not be connected to
any system that contains trolley wires with a ground return.

Exception: Such circuit connections shall be permitted in
car houses, power houses, or passenger and freight
stations operated in connection with electric railways.

70-34

2010 California Electrical Code

ARTICLE no - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

110.21

110,21 Marking. The manufacturer's name, trademark, or
other descriptive marking by which the organization
responsible for the product can be identified shall be placed
on all electrical equipment. Other markings that indicate
voltage, current, wattage, or other ratings shall be provided
as specified elsewhere in this Code. The marking shall be of
sufficient durability to withstand the environment involved.

Table 110.20 Enclosure Selection

Provides a Degree of Protection Against
the Following Environmental Conditions

For Outdoor Use

Enclosure-Type Number

3RX

3SX

Incidental contact with the enclosed
equipment

Rain, snow, and sleet

Sleet*

—

-—

—

Windblown dust

—

Hosedown

—

Corrosive agents

—

Temporary submersion

—

Prolonged submersion

—

Provides a Degree of Protection Against
the Following Environmental Conditions

For Indoor Use

Enclosure Type Number

12K

Incidental contact with the enclosed
equipment

Falling dirt

Falling liquids and light splashing

—

Circulating dust, lint, fibers, and flyings

—

Settling airborne dust, lint, fibers, and
flyings

—

Hosedown and splashing water

—

Oil and coolant seepage

—

Oil or coolant spraying and splashing

—

Corrosive agents

—

Temporary submersion

—

Prolonged submersion

—

♦Mechanism shall be operable when ice covered.

FPN: The term raintight is typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 4, 4X, 6, and 6P. The term rainproof is
typically used in conjunction with Enclosure Types 3R, and 3RX. The term watertight is typically used in conjunction with Enclosure
Types 4, 4X, 6, 6P. The term driptight is typically used in conjunction with Enclosure Types 2, 5, 12, 12K, and 13. The term dusttight is
typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 5, 12, 12K, and 13.

2010 California Electrical Code

70-35

110.22

ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

110.22 Identification of Disconnecting Means.

(A) GeneraL Each disconnecting means shall be legibly
marked to indicate its purpose unless located and arranged
so the purpose is evident. The marking shall be of
sufficient durability to withstand the environment involved.

(B) Engineered Series Combiiialdan Sysfems/ Where;
circuit breakers or fuses are applied in coniplianc^ witH
relies :combinrtion iratings selected vmder engineering
isupervision ; and marked : on the equipment as directed h^i
the engineer, the equipnient enclbsure(s) shall be legibly
marked in the field to indicate tteeqiiipin^nt has H^^^^
applied with a series combiiiaddii ratmg;=Th;elM^i1d

be readily visible and state; tlie follo^dng:

CAimoN. ■■ :''™-''~- -■■■^■iNGiMlMo'^

CQMBiNATIDN SYSTEM RAXED AMPERES^

identified ; replacement l^omponejnts
requiMdI

FPN: 'See '24d.86(A)^,fet;i^^ngme^
systems,

(C) Tested , Series Coinbihatto^ Where circuit
breakers or fuses are applied in compliance with the series
combination ratings marked on the equipment by the
manufacturer, the equipment enclosure(s) shall be legibly
marked in the field to indicate the equipment has been
applied with a series combination rating. The marking shall
be readily visible and state the following:

CAUTION — SERIES COMBINATION SYSTEM

RATED AMPERES. IDENTIFIED

REPLACEMENT COMPONENTS REQUIRED.
FPN: See 240.86(B) for fested seriesxomto

110.23 Current Transformers. Unused current
transformers associated with potentially energized circuits
shall be short-circuited.

II. 600 Volts, Nominal, or Less

110.26 Spaces About Electrical Equipment. Sufficient
access and working space shall be provided and maintained
about all electrical equipment to permit ready and safe
operation and maintenance of such equipment.

(A) Working Space. Working space for equipment
operating at 600 volts, nominal, or less to ground and likely
to require examination, adjustment, servicing, or
maintenance while energized shall comply with the
dimensions of 110.26(A)(1), (A)(2), and (A)(3) or as
required or permitted elsewhere in this Code,

(1) Depth of Working Space. The depth of the working
space in the direction of live parts shall not be less than that
specified in Table 110.26(A)(1) unless the requirements of
110.26(A)(1)(a), (A)(1)(b), or (A)(1)(c) are met. Distances
shall be measured from the exposed live parts or from the
enclosure or opening if the live parts are enclosed.

Table 110.26(A)(1) Working Spaces

Minimum Clear Distance

Nominal

Voltage to

Ground

Condition 1 Condition 2 Condition 3

0-150
151-600

:9:M mm (3 ft) W4 mm (3 ft) Wi mm (3 ft)
|l4mm(3ft) |:^m(3ft6in.) I22m(4ft)

Note: Where the conditions are as follows:
Condition 1 — Exposed live parts on one side of the working
space and no live or grounded parts on the other side of the
working space, or exposed live parts on both sides of the working
space that are effectively guarded by insulating materials.
Condition 2 — Exposed live parts on one side of the working
space and grounded parts on the other side of the working space.
Concrete, brick, or tile walls shall be considered as grounded.
Condition 3 — Exposed live parts on both sides of the working
space.

(a) Dead-Front Assemblies. Working space shall not be
required in the back or sides of assemblies, such as dead-front
switchboards or motor control centers, where all connections
and all renewable or adjustable parts, such as fuses or switches,
are accessible from locations other than the back or sides.
Where rear access is required to work on nonelectrical parts on
the back of enclosed equipment, a minimum horizontal working
space of 762 mm (30 in.) shall be provided.

(b) Low Voltage. By special permission, smaller
working spaces shall be permitted where all exposed live
parts operate at not greater than 30 volts rms, 42 volts peak,
or 60 volts dc.

(c) Existing Buildings. In existing buildings where
electrical equipment is being replaced. Condition 2
working clearance shall be permitted between dead-front
switchboards, panelboards, or motor control centers located
across the aisle from each other where conditions of
maintenance and supervision ensure that written procedures
have been adopted to prohibh equipment on both sides of
the aisle from being open at the same time and qualified
persons who are authorized will service the installation.

(2) Width of Working Space. The width of the working
space in front of the electrical equipment shall be the width
of the equipment or |j6l mm (30 in.), whichever is greater.
In all cases, the work space shall permit at least a 90 degree
opening of equipment doors or hinged panels.

(3) Height of Working Space. The work space shall be clear
and extend from the grade, floor, or platform to the height
required by 110.26(E). Within the height requirements of this
section, other equipment that is associated with the electrical
installation and is located above or below the electrical
equipment shall be permitted to extend not more than 150 mm
(6 in.) beyond the front of the electrical equipment.

(B) Clear Spaces. Working space required by this section
shall not be used for storage. When normally enclosed live
parts are exposed for inspection or servicing, the working
space, if in a passageway or general open space, shall be
suitably guarded.

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20 1 California Electrical Code

ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

110.26

(1) Minimum Required. At least one entrance of
sufficient area shall be provided to give access to ffitj
|e^#e'ss;fr$iq working space about electrical equipment.

(2) Large EqmgmentJ^ rated 1200 amperes
or more SgJOTer::3tg:^=^^^ that contains
overcurrent devices, switching devices^or control devices,
there shall be one entrance to ind ;0ff<^ss|fe the required
working space not less than 610 mm (24 in.) wide and 2.0
m (6V2 ft) high at each end of the working space.

A single entrance to gS^igress Jfroimi the required
working space shall be permitted where either of the
conditions in 1 10.26(C)(2)(a) or (C)(2)(b) is met.

(a) Unobstructed Egress. WhevQ the location permits a
continuous and unobstructed way of iep^ssj travel, a single
entrance to the working space shall be permitted.

(b) Extra Working Space. Where the depth of the working
space is twice that required by 110.26(A)(1), a single entrance
shall be permitted. It shall be located such that the distance from
the equipment to the nearest edge of the entrance is not less than
the minimum clear distance specified in Table 1 10.26(A)(1) for
equipment operating at that voltage and in that condition.

i:3)[:r/PW|omiei; 'ipi^^^^

mote that contiM ^Witching! devices, oi

oonprp\Myic€^:miM^ is a ;pers<>imerdpor(s)

^n^rided for;eiite to atid: egress, ^oinJtheJwbfkiagspa^^^
less than 17.6; m (25;fl:); firpm the nearest edge of the working-

feat ar^ ijprmally latched but open under Simple pressureJ

(D) Illumination. Illumination shall be provided for all

working spaces about service equipment, switchboards,
panelboards, or motor control centers installed indoors.
Additional lighting outlets shall not be required where the
work space is illuminated by an adjacent light source or as
permitted by 210.70(A)(1), Exception No. I, for switched
receptacles. In electrical equipment rooms, the illumination
shall not be controlled by automatic means only.

(E) Headroom. The minimum headroom of working
spaces about service equipment, switchboards,
panelboards, or motor control centers shall be 2.0 m (6V2
ft). Where the electrical equipment exceeds 2.0 m (6V2 ft)
in height, the minimum headroom shall not be less than the
height of the equipment.

Exception: In existing dwelling units, service equipment or
panelboards that do not exceed 200 amperes shall be
permitted in spaces where the headroom is less than 2.0 m
(6'Aft).

(F) Dedicated Equipment Space. All switchboards,
panelboards, distribution boards, and motor control centers
shall be located in dedicated spaces and protected from
damage.

Exception: Control equipment that by its very nature or
because of other rules of the Code must be adjacent to or
within sight of its operating machinery shall be permitted
in those locations.

(1) Indoor. Indoor installations shall comply with
1 10.26(F)(1)(a) through (F)(1)(d).

(a) Dedicated Electrical Space. The space equal to the
width and depth of the equipment and extending from the
floor to a height of 1.8 m (6 ft) above the equipment or to
the structural ceiling, whichever is lower, shall be
dedicated to the electrical installation. No piping, ducts,
leak protection apparatus, or other equipment foreign to the
electrical installation shall be located in this zone.

Exception: Suspended ceilings with removable panels
shall be permitted within the 1.8-m (6-ft) zone.

(b) Foreign Systems. The area above the dedicated
space required by 110.26(F)(1)(a) shall be permitted to
contain foreign systems, provided protection is installed to
avoid damage to the electrical equipment from
condensation, leaks, or breaks in such foreign systems.

(c) Sprinkler Protection. Sprinkler protection shall be
permitted for the dedicated space where the piping
complies with this section.

(d) Suspended Ceilings. A dropped, suspended, or
similar ceiling that does not add strength to the building
structure shall not be considered a structural ceiling.

(2) Outdoor. Outdoor electrical equipment shall be
installed in suitable enclosures and shall be protected from
accidental contact by unauthorized personnel, or by
vehicular traffic, or by accidental spillage or leakage from
piping systems. The working clearance space shall include
the zone described in 1 10.26(A). No architectural
appurtenance or other equipment shall be located in this
zone.

p&)''iLocked lilecirtcaf iEqiiip or .Enclosures^

fel^trie^l equipment x^^ housing electrical

^araWi^ ■ that; ; ^ei :cc«iiiix)lted ; : l^y a lock;(s) shall bd

110.27 Guarding of Live Parts.

(A) Live Parts Guarded Against Accidental Contact.

Except as elsewhere required or permitted by this Code,
live parts of electrical equipment operating at 50 volts or
more shall be guarded against accidental contact by
approved enclosures or by any of the following means:

(1) By location in a room, vault, or similar enclosure that
is accessible only to qualified persons.

(2) By suitable permanent, substantial partitions or screens
arranged so that only qualified persons have access to
the space within reach of the live parts. Any openings
in such partitions or screens shall be sized and located
so that persons are not likely to come into accidental

2010 California Electrical Code

70™37

110.27

ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

contact with the live parts or to bring conducting
objects into contact with them.

(3) By location on a suitable balcony, gallery, or platform
elevated and arranged so as to exclude unqualified
persons.

(4) By elevation of 2.5 m (8 ft) or more above the floor or
other working surface.

(B) Prevent Physical Damage. In locations where
electrical equipment is likely to be exposed to physical
damage, enclosures or guards shall be so arranged and of
such strength as to prevent such damage.

(C) Warning Signs. Entrances to rooms and other guarded
locations that contain exposed live parts shall be marked
with conspicuous warning signs forbidding unqualified
persons to enter.

FPN: For motors, see 430.232 and 430.233. For over 600
volts, see 110.34.

III. Over 600 Volts, Nominal

110.30 General. Conductors and equipment used on
circuits over 600 volts, nominal, shall comply with Part I of
this article and with 110,30 through 110.40, which
supplement or modify Part I. In no case shall the provisions
of this part apply to equipment on the supply side of the
service point.

110.31 Enclosure for Electrical Installations. Electrical
installations in a vault, room, or closet or in an area
surrounded by a wall, screen, or fence, access to which is
controlled by a lock(s) or other approved means, shall be
considered to be accessible to qualified persons only. The
type of enclosure used in a given case shall be designed
and constructed according to the nature and degree of the
hazard(s) associated with the installation.

For installations other than equipment as described in
1 10.31(D), a wall, screen, or fence shall be used to enclose
an outdoor electrical installation to deter access by persons
who are not qualified, or a combination of 1.8 m (6 ft) or
more of fence fabric and a 300-mm (1-ft) or more
extension utilizing three or more strands of barbed wire or
equivalent. The distance from the fence to live parts shall
be not less than given in Table 1 10.3 1 .

Table 110.31 Minimum Distance from Fence to Live Parts

Nominal Voltage

Minimum Distance to Live Parts

601-13,799

3.05

13,800-230,000

4.57

Over 230,000

5.49

Note: For clearances of conductors for specific system voltages
and typical BIL ratings, see ANSI C2-2007, National Electrical
Safety Code.

FPN: See Article 450 for construction requirements for
transformer vaults.

(A) Fire Resiis^iied of Electrical Vaults. The walls, roof,
floors, and doorways of vaults containing conductors and
equipment over 600 volts, nominal, shall be constructed of
materials that have adequate structural strength for the
conditions, with a minimum fire rating of 3 hours.

For the purpose of this section, studs and wallboards shall
not be considered acceptable.

(B) Indoor Installations.

(1) In Places Accessible to Unqualified Persons. Indoor
electrical installations that are accessible to unqualified
persons shall be made with metal-enclosed equipment.
Metal-enclosed switchgear, unit substations, transformers,
pull boxes, connection boxes, and other similar associated
equipment shall be marked with appropriate caution signs.
Openings in ventilated dry-type transformers or similar
openings in other equipment shall be designed so that
foreign objects inserted through these openings are
deflected from energized parts.

(2) In Places Accessible to Qualified Persons Only.

Indoor electrical installations considered accessible only to
qualified persons in accordance with this section shall
comply with 1 10.34, 1 10.36, and 490.24.

(1) In Places Accessible to Unqualified Persons.

Outdoor electrical installations that are open to unqualified
persons shall comply with Parts I, II, and III of Article 225.

(2) In Places Accessible to Qualified Persons Only.

Outdoor electrical installations that have exposed live parts
shall be accessible to qualified persons only in accordance
with the first paragraph of this section and shall comply
with 110.34, 110.36, and 490.24.

70-38

2010 California Electrical Code

ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

110.34

(D) Enclosed Equipment Accessible to Unqualified
Persons. Ventilating or similar openings in equipment
shall be designed such that foreign objects inserted through
these openings are deflected from energized parts. Where
exposed to physical damage from vehicular traffic, suitable
guards shall be provided. Nonmetallic or metal-enclosed
equipment located outdoors and accessible to the general
public shall be designed such that exposed nuts or bolts
cannot be readily removed, permitting access to live parts.
Where nonmetallic or metal-enclosed equipment is
accessible to the general public and the bottom of the
enclosure is less than 2.5 m (8 ft) above the floor or grade
level, the enclosure door or hinged cover shall be kept
locked. Doors and covers of enclosures used solely as pull
boxes, splice boxes, or junction boxes shall be locked,
bolted, or screwed on. Underground box covers that weigh
over 45.4 kg (100 lb) shall be considered as meeting this
requirement.

110.32 Work Space About Equipment. Sufficient space
shall be provided and maintained about electrical
equipment to permit ready and safe operation and
maintenance of such equipment. Where energized parts are
exposed, the minimum clear work space shall be not less
than 2.0 m (6V2 ft) high (measured vertically from the floor
or platform) or not less than 9|3 mm (3 ft) wide (measured
parallel to the equipment). The depth shall be as required in
1 10.34(A). In all cases, the work space shall permit at least
a 90 degree opening of doors or hinged panels.

11033 Entrance p Enclosuresl and Access to WoiMtg Space.

(A) Entrance. At least one entrance to eiiqiqswes f4^
?l??!ri<^§I|s?^?il§*i<>^^^ ^ d^^^ribed in 1 103|

(1) Large Equipment. On switchboard and control panels
exceeding 1.8 m (6 ft) in width, there shall be one entrance
at each end of the equipment. A single entrance to the
required working space shall be permitted where either of
the conditions in 1 10.33(A)(1)(a) or (A)(1)(b) is met.

(a) Unobstructed Exit. Where the location permits a
continuous and unobstructed way of exit travel, a single
entrance to the working space shall be permitted.

(b) Extra Working Space. Where the depth of the working
space is twice that required by 1 10.34(A), a single entrance shall
be permitted. It shall be located so that the distance from the
equipment to the nearest edge of the entrance is not less than the
minimum clear distance specified in Table 110.34(A) for
equipment operating at that voltage and in that condition.

(2) Guarding. Where bare energized parts at any voltage
or insulated energized parts above 600 vohs, nominal, to
ground are located adjacent to such entrance, they shall be
suitably guarded.

(|>; ;:|ers6Mel;;P^or^^ ;W}iare ,th^re is;a:|>erspmerdooi;(s)
mtm^^§\ for ~ ^nikmce. to '' ani egress , ftpm' Ihe :w6tMh^^ space
fes jtHan tT^sSII.,^ .§9^: ^^ ^f^?,®?f.?dge;of ;thej w^
|pac4j|edop^|);^

l^m^ped wW^ 1^ tes^pres^ej plates, or other devites
iMt £e nonmlJb^ Hohc^^^ opoi tmder shnple pres^urei^
(B) Access. Permanent ladders or stairways shall be
provided to give safe access to the working space around
electrical equipment installed on platforms, balconies, or
mezzanine floors or in attic or roof rooms or spaces.
110.34 Work Space and Guarding.

(A) Worldng Space. Except as elsewhere required or
permitted in this Code, Sqip^||it^{ jSj^^^^^^

la^gize^ ;sh§]^aye clear working space in the direction of
access to live parts of ilia electrical equipment md shall be
not less than specified in Table 110.34(A). Distances shall
be measured fi-om the live parts, if such are exposed, or
fi-om the enclosure firont or opening if such are enclosed.

Exception: Working space shall not be required in back of
equipment such as dead-front switchboards or control
assemblies where there are no renewable or adjustable parts
(such as fuses or switches) on the back and where all
connections are accessible from locations other than the back.

Table 110.34(A) Minimum Depth of Clear Working Space at
Electrical Equipment

Minimum Clear Distance

Nominal Voltage

to Ground Condition 1 Condition 2 Condition 3

601-2500 V 900 mm (3 ft) 1 .2 m (4 ft) 1.5 m (5 ft)
2501-9000 V 1.2 m (4 ft) 1.5 m (5 ft) 1.8 m (6 ft)

9001-25,000 V 1.5 m (5 ft) 1.8 m (6 ft) 2.8 m (9 ft)
25,001 V-75kV 1.8 m (6 ft) 2.5 m (8 ft) 3.0 m (10 ft)
Above 75 kV 2.5 m (8 ft) 3.0 m (10 ft) 3.7 m (12 ft)

(B) Separation from Low-Voltage Equipment. Where
sv^itches, cutouts, or other equipment operating at 600
volts, nominal, or less are installed in a vault, room, or
enclosure v^here there are exposed live parts or exposed
wiring operating at over 600 vohs, nominal, the high-
voltage equipment shall be effectively separated from the
space occupied by the lov^-voltage equipment by a suitable
partition, fence, or screen.

2010 California Electrical Code

70-39

110.36

ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

Exception: Switches or other equipment operating at 600
volts, nominal, or less and serving only equipment within
the high-voltage vault, room, or enclosure shall be
permitted to be installed in the high-voltage vault, room, or
enclosure without a partition, fence, or screen if accessible
to qualified persons only.

(C) Locked Rooms or Enclosures. The entrance to all
buildings, vaults, rooms, or enclosures containing exposed
live parts or exposed conductors operating at over 600
volts, nominal, shall be kept locked unless such entrances
are under the observation of a qualified person at all times.

Where the voltage exceeds 600 volts, nominal,
permanent and conspicuous warning signs shall be
provided, reading as follows:

DANGER — HIGH VOLTAGE — KEEP OUT

(D) Illumination. Illumination shall be provided for all
working spaces about electrical equipment. The lighting
outlets shall be arranged so that persons changing lamps or
making repairs on the lighting system are not endangered
by live parts or other equipment.

The points of control shall be located so that persons
are not likely to come in contact with any live part or
moving part of the equipment while turning on the lights.

(E) Elevation of Unguarded Live Parts. Unguarded Hve
parts above working space shall be maintained at elevations
not less than required by Table 1 10.34(E).

Table 110.34(E) Elevation of Unguarded Live Parts Above
Working Space

Elevation

Nominal Voltage
Between Phases

601-7500 V

2.8

7501-35,000 V

2.9

9 ft 6 in.

Over 35 kV

2.9

m + 9.5 mm/kV
above 35

9ft6in.+0.37
in./kV above 35

(F) Protection of Service Equipment, Metal-Enclosed
Power Switchgear, and Industrial Control Assemblies.

Pipes or ducts foreign to the electrical installation and
requiring periodic maintenance or whose malfunction would
endanger the operation of the electrical system shall not be
located in the vicinity of the service equipment, metal-
enclosed power switchgear, or mdustrial control assemblies.
Protection shall be provided where necessary to avoid damage
from condensation leaks and breaks in such foreign systems.
Piping and other facilities shall not be considered foreign if
provided for fire protection of the electrical installation.

110.36 Circuit Conductors. Circuit conductors shall be
permitted to be installed in raceways; in cable trays; as
metal-clad cable, as bare wire, cable, and busbars; or as

Type MV cables or conductors as provided in 300.37,
300.39, 300.40, and 300.50. Bare live conductors shall
comply with 490.24.

Insulators, together with their mounting and conductor
attachments, where used as supports for wires, single-
conductor cables, or busbars, shall be capable of safely
withstanding the maximum magnetic forces that would
prevail if two or more conductors of a circuit were
subjected to short-circuit current.

Exposed runs of insulated wires and cables that have a
bare lead sheath or a braided outer covering shall be
supported in a manner designed to prevent physical damage
to the braid or sheath. Supports for lead-covered cables
shall be designed to prevent electrolysis of the sheath.

110.40 Temperature Limitations at Terminations.

Conductors shall be permitted to be terminated based on
the 90°C (194°F) temperature rating and ampacity as
given in Table 310.67 through Table 310.86, unless
otherwise identified.

IV. Tunnel Installations over 600 Volts, Nominal

110.51 General.

(A) Covered. The provisions of this part shall apply to the
installation and use of high-voltage power distribution and
utilization equipment that is portable, mobile, or both, such
as substations, trailers, cars, mobile shovels, draglines,
hoists, drills, dredges, compressors, pumps, conveyors,
underground excavators, and the like.

(B) Other Articles, The requirements of this part shall be
additional to, or amendatory of, those prescribed in Articles
100 through 490 of this Code.

(C) Protection Against Physical Damage. Conductors and
cables in tunnels shall be located above the tunnel floor and
so placed or guarded to protect them from physical damage.

110.52 Overcurrent Protection. Motor-operated
equipment shall be protected from overcurrent in
accordance with Parts III, IV, and V of Article 430.
Transformers shall be protected from overcurrent in
accordance with 450.3.

110.53 Conductors. High- voltage conductors in tunnels
shall be installed in metal conduit or other metal raceway,
Type MC cable, or other approved multiconductor cable.
Multiconductor portable cable shall be permitted to supply
mobile equipment.

110.54 Bonding and Equipment Grounding
Conductors.

(A) Grounded and Bonded. All non-current-carrying
metal parts of electrical equipment and all metal raceways
and cable sheaths shall be soiidl3^ grounded and bonded to
all metal pipes and rails at the portal and at intervals not
exceeding 300 m (1000 ft) throughout the tunnel.

•

70-40

2010 California Electrical Code

ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

110.72

(B) Equipment Grounding Conductors. An equipment
grounding conductor shall be run with circuit conductors
inside the metal raceway or inside the multiconductor cable
jacket. The equipment grounding conductor shall be
permitted to be insulated or bare.

110.55 Transformers, Switches, and Electrical
Equipment. All transformers, switches, motor controllers,
motors, rectifiers, and other equipment installed
belowground shall be protected from physical damage by
location or guarding.

110.56 Energized Parts. Bare terminals of transformers,
switches, motor controllers, and other equipment shall be
enclosed to prevent accidental contact with energized parts.

110.57 Ventilation System Controls. Electrical controls
for the ventilation system shall be arranged so that the
airflow can be reversed.

110.58 Disconnecting Means. A switch or circuit breaker
that simultaneously opens all ungrounded conductors of the
circuit shall be installed within sight of each transformer or
motor location for disconnecting the transformer or motor.
The switch or circuit breaker for a transformer shall have
an ampere rating not less than the ampacity of the
transformer supply conductors. The switch or circuit
breaker for a motor shall comply with the applicable
requirements of Article 430.

110.59 Enclosures. Enclosures for use in tunnels shall be
dripproof, weatherproof, or submersible as required by the
environmental conditions. Switch or contactor enclosures
shall not be used as junction boxes or as raceways for
conductors feeding through or tapping off to other
switches, unless the enclosures comply with 312.8.

V. Manholes and Other Electrical Enclosures Intended
for Personnel Entry, All Voltages

110.70 General. Electrical enclosures intended for
personnel entry and specifically fabricated for this purpose
shall be of sufficient size to provide safe work space about
electrical equipment with live parts that is likely to require
examination, adjustment, servicing, or maintenance while
energized. Such enclosures shall have sufficient size to
permit ready installation or withdrawal of the conductors
employed without damage to the conductors or to their
insulation. They shall comply with the provisions of this
part.

Exception: Where electrical enclosures covered by Part V
of this article are part of an industrial wiring system
operating under conditions of maintenance and supervision
that ensure that only qualified persons monitor and
supervise the system, they shall be permitted to be designed
and installed in accordance with appropriate engineering
practice. If required by the authority having jurisdiction,
design documentation shall be provided.

110.71 Strength. Manholes, vaults, and their means of
access shall be designed under qualified engineering
supervision and shall withstand all loads likely to be
imposed on the structures.

FPN: See ANSI C2-2007, National Electrical Safety Code,
for additional information on the loading that can be
expected to bear on underground enclosures.

110.72 Cabling Work Space. A clear work space not less
than 900 mm (3 ft) wide shall be provided where cables are
located on both sides, and not less than 750 mm {IVi ft)
where cables are only on one side. The vertical headroom
shall be not less than 1.8 m (6 ft) unless the opening is
within 300 mm (1 ft), measured horizontally, of the
adjacent interior side wall of the enclosure.

Exception: A manhole containing only one or more of the
following shall be permitted to have one of the horizontal
work space dimensions reduced to 600 mm (2 ft) where the
other horizontal clear work space is increased so the sum
of the two dimensions is not less than 1.8 m (6 ft):

(1) Optical fiber cables as covered in Article 770

(2) Power-limited fire alarm circuits supplied in
accordance with 760lftii

(3) Class 2 or Class 3 remote-control and signaling
circuits, or both, supplied in accordance with 72^:121

110.73 Equipment Work Space. Where electrical
equipment with live parts that is likely to require
examination, adjustment, servicing, or maintenance while
energized is installed in a manhole, vault, or other
enclosure designed for personnel access, the work space
and associated requirements in 110.26 shall be met for
installations operating at 600 volts or less. Where the
installation is over 600 volts, the work space and associated
requirements in 110.34 shall be met. A manhole access
cover that weighs over 45 kg (100 lb) shall be considered
as meeting the requirements of 1 10.34(C).

2010 California Electrical Code

70-41

110.73

ARTICLE 110- REQUIREMENTS FOR ELCTRICAL INSTALLATIONS

110.74 Bending Space for Conductors. Bending space for
conductors operating at 600 volts or below shall be provided
in accordance with the requirements of 314.28. Conductors
operating at over 600 volts shall be provided with bending
space in accordance with 314.71(A) and 314.71(B), as
applicable. All conductors shall be cabled, racked up, or
arranged in an approved manner that provides ready and safe
access for persons to enter for installation and maintenance.

Exception: Where 314.71(B) applies, each row or column
of ducts on one wall of the enclosure shall be calculated
individually, and the single row or column that provides
the maximum distance shall be used.

110.75 Access to Manholes.

(A) Dimensions. Rectangular access openings shall not be
less than 650 mm x 550 mm (26 in. x 22 in.). Round access
openings in a manhole shall be not less than 650 mm (26
in.) in diameter.

Exception: A manhole that has a fixed ladder that does not
obstruct the opening or that contains only one or more of
the following shall be permitted to reduce the minimum
cover diameter to 600 mm (2 ft):

(1) Optical fiber cables as covered in Article 770

(2) Power-limited fire alarm circuits supplied in
accordance with 760:l2l\

(3) Class 2 or Class 3 remote-control and signaling
circuits, or both, supplied in accordance with '/25J2i

(B) Obstructions. Manhole openings shall be free of
protrusions that could injure personnel or prevent ready
egress.

(C) Location. Manhole openings for personnel shall be
located where they are not directly above electrical equipment
or conductors in the enclosure. Where this is not practicable,
either a protective barrier or a fixed ladder shall be provided.

(D) Covers. Covers shall be over 45 kg (100 lb) or
otherwise designed to require the use of tools to open. They
shall be designed or restrained so they cannot fall into the
manhole or protrude sufficiently to contact electrical
conductors or equipment within the manhole.

(E) Marking. Manhole covers shall have an identifying
mark or logo that prominently indicates their function, such
as "electric."

110.76 Access to Vaults and Tunnels.

(A) Location. Access openings for personnel shall be
located where they are not directly above electrical
equipment or conductors in the enclosure. Other openings
shall be permitted over equipment to facilitate installation,
maintenance, or replacement of equipment.

(B) Locks. In addition to compliance with the requirements
of 1 10.34, if applicable, access openings for personnel shall
be arranged such that a person on the inside can exit when
the access door is locked from the outside, or in the case of
normally locking by padlock, the locking arrangement shall
be such that the padlock can be closed on the locking
system to prevent locking from the outside.

110.77 Ventilation. Where manholes, tunnels, and vaults
have communicating openings into enclosed areas used by
the public, ventilation to open air shall be provided
wherever practicable.

110.78 Guarding. Where conductors or equipment, or
both, could be contacted by objects falling or being pushed
through a ventilating grating, both conductors and live
parts shall be protected in accordance with the
requirements of 110.27(A)(2) or 110.31(B)(1), depending
on the voltage,

110.79 Fixed Ladders. Fixed ladders shall be corrosion resistant.

70^2

2010 California Electrical Code

CHAPTER 2 CALIFORNIA MATRIX ADOPTION TABLE

CHAPTER 2 - WIRING AND PROTECTION

Adopting Agency

BSC

SFM

HCD

DSA

OSHPD

DPH

ss/cc

Adopt Entire Chapter

Adopt Entire Chapter as amended
(amended sections listed below)

Adopt only those articles / sections that
are listed below

Article / Section

210.50(D). (E)

220 / Table 220.42

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.

2010 California Electrical Code

70-42.1

CHAPTER 2 CALIFORNIA MATRIX ADOPTION TABLE

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.
'^^■^^'^ 2010 California Electrical Code

ARTICLE 200 - USE AND IDENTIFICATION OF GROUNDED CONDUCTORS

200.6

Chapter 2 Wiring and Protection

iJie and Idgntipeation 0f Grounded

200.1 Scope.

following:

This article provides requirements for the

(1) Identification of terminals

(2) Grounded conductors in premises wiring systems

(3) Identification of grounded conductors

FPN: See Article 100 for definitions of Grounded
Conductor and Grounding Conductor.

200,2 General. All premises wiring systems, other than
circuits and systems exempted or prohibited by 210.10,
215.7, 250.21, 250.22, 250.162, 503.155, 517.63, 668.11,
668.21, and 690.41, Exception, shall have a grounded
conductor that is identified in accordance with 200.6. |p|^

^gr^dedtqadjacto^^ and (B).

(S) JDttiul|ti0it. The grounded conductor, where insulated,
shall have insulation that is (1) suitable, other than color,
for any ungrounded conductor of the same circuit on
circuits of less than 1000 volts or impedance grounded
neutral systems of 1 kV and over, or (2) rated not less than
600 volts for solidly grounded neutral systems of 1 kV and
over as described in 250.184(A).

(9) C^OT^»uity.;Tfe Qpntiiimty of a gi:0^hjded ooncluctoij

shall"; laot &p^d: ^OB^a', <?'o^

200.3 Connection to Grounded System. Premises wiring
shall not be electrically connected to a supply system
unless the latter contains, for any grounded conductor of
the interior system, a corresponding conductor that is
grounded. For the purpose of this section, electrically
connected shall mean connected so as to be capable of
carrying current, as distinguished from connection through
electromagnetic induction.

Exception: tfytedmHUi^tr0^m^^

m^9m'\dMrikui)^d'\ rksomt^i ^^<^^mfion[ tsyMkini such ; as

ph^iqv(:>ltdi0 anafiie-l c0]^pi^: s^iems:^ ^H^U \Q0^etfhiited

h^h^tm wfi^re ' the [ (x^nmci^'jpr'em^^ '.W-^.^& W. V^'Wty^
■§yit0minplu<^l-agr0tmd^^^^

200.6 Means of Identifying Grounded Conductors.

(A) Sizes 6 AWG or Smaller. An insulated grounded
conductor of 6 AWG or smaller shall be identified by a
continuous white or gray outer finish or by three

continuous white stripes on other than green insulation
along its entire length. Wires that have their outer covering
finished to show a white or gray color but have colored
tracer threads in the braid identifying the source of
manufacture shall be considered as meeting the provisions
of this section. Insulated grounded conductors shall also be
permitted to be identified as follows:

(1) The grounded conductor of a mineral-insulated, metal-
sheathed cable shall be identified at the time of
installation by distinctive marking at its terminations.

(2) A single-conductor, sunlight-resistant, outdoor-rated
cable used as a grounded conductor in photovoltaic
power systems as permitted by 690.31 shall be
identified at the time of installation by distinctive
white marking at all terminations.

(3) Fixture wire shall comply with the requirements for
groxmded conductor identification as specified in
402.8.

(4) For aerial cable, the identification shall be as above, or
by means of a ridge located on the exterior of the cable
so as to identify it.

(B) Sizes Larger Than 6 AWG. An insulated grounded
conductor larger than 6 AWG shall be identified by one of
the following means:

(1) By a continuous white or gray outer finish.

(2) By three continuous white stripes along its entire
length on other than green insulation.

(3) At the time of installation, by a distinctive white or
gray marking at its terminations. This marking shall
encircle the conductor or insulation.

(C) Flexible Cords. An insulated conductor that is
intended for use as a grounded conductor, where contained
within a flexible cord, shall be identified by a white or gray
outer finish or by methods permitted by 400.22.

(D) Grounded Conductors of Different Systems. Where

grounded conductors of different systems are installed in the
same raceway, cable, box, auxiliary gutter, or other type of
enclosure, each grounded conductor shall be identified by
system. Identification that distinguishes each system grounded
conductor shall be permitted by one of the following means:

(1) One system grounded conductor shall have an outer
covering conforming to 200,6(A) or (B).

(2) The grounded conductor(s) of other systems shall have
a different outer covering conforming to 200.6(A) or
200.6(B) or by an outer covering of white or gray with
a readily distinguishable colored stripe other than
green running along the insulation.

2010 California Electrical Code

70-43

200.7

ARTICLE 200 - USE AND IDENTIFICATION OF GROUNDED CONDUCTORS

(3) Other and different means of identification as allowed by
200.6(A) or (B) that will distinguish each system
grounded conductor. This means of identification shall
be permanently posted at each branch-circuit panelboard.

(E) Grounded Conductors of Multiconductor Cables.

The insulated grounded conductors in a multiconductor cable
shall be identified by a continuous white or gray outer finish
or by three continuous white stripes on other than green
insulation along its entire length. Multiconductor flat cable 4
AWG or larger shall be permitted to employ an external
ridge on the grounded conductor.

Exception No. 1: Where the conditions of maintenance and
supervision ensure that only qualified persons service the
installation, grounded conductors in multiconductor cables
shall be permitted to be permanently identified at their
terminations at the time of installation by a distinctive
white marking or other equally effective means.

Exception No. 2: The grounded conductor of a
multiconductor varnished-cloth-insulated cable shall be
permitted to be identified at its terminations at the time of
installation by a distinctive white marking or other equally
effective means.

FPN: The color gray may have been used in the past as an
ungrounded conductor. Care should be taken when working
on existing systems.

200.7 Use of Insulation of a White or Gray Color or
with Three Continuous White Stripes.

(A) General. The following shall be used only for the
grounded circuit conductor, unless otherwise permitted in
200.7(B) and (C):

(1) A conductor with continuous white or gray covering

(2) A conductor with tfu-ee continuous white stripes on
other than green insulation

(3) A marking of white or gray color at the termination

(B) Circuits of Less Than 50 Volts. A conductor with
white or gray color insulation or three continuous white
stripes or having a marking of white or gray at the
termination for circuits of less than 50 volts shall be
required to be grounded only as required by 250.20(A).

(C) Circuits of 50 Volts or More. The use of insulation that
is white or gray or that has three continuous white stripes for
other than a grounded conductor for circuits of 50 volts or
more shall be permitted only as in (1) through (3).

(I) If part of a cable assembly and where the insulation is
permanently reidentified to indicate its use as an
ungrounded conductor, by painting or other effective
means at its termination, and at each location where
the conductor is visible and accessible. Identification
shall encircle the insulation and shall be a color other
than white, gray, or green.

(2) Where a cable assembly contains an insulated
conductor for single-pole, 3 -way or 4-way switch
loops and the conductor with white or gray insulation
or a marking of three continuous white stripes is used
for the supply to the switch but not as a return
conductor fi*om the switch to the switched outlet. In
these applications, the conductor with white or gray
insulation or with three continuous white stripes shall
be permanently reidentified to indicate its use by
painting or other effective means at its terminations
and at each location where the conductor is visible and
accessible.

(3) Where a flexible cord, having one conductor identified
by a white or gray outer finish or three continuous white
stripes or by any other means permitted by 400.22, is
used for connecting an appliance or equipment
permitted by 400.7. This shall apply to flexible cords
connected to outlets whether or not the outlet is supplied
by a circuit that has a grounded conductor.

FPN: The color gray may have been used in the past as an
ungrounded conductor. Care should be taken when working
on existing systems.

200.9 Means of Identification of Terminals. The

identification of terminals to which a grounded conductor
is to be connected shall be substantially white in color. The
identification of other terminals shall be of a readily
distinguishable different color.

Exception: Where the conditions of maintenance and
supervision ensure that only qualified persons service the
installations, terminals for grounded conductors shall be
permitted to be permanently identified at the time of installation
by a distinctive white marking or other equally effective means.

200.10 Identification of Terminals.

(A) Device Terminals. All devices, excluding panelboards,
provided with terminals for the attachment of conductors
and intended for connection to more than one side of the
circuit shall have terminals properly marked for
identification, unless the electrical connection of the
terminal intended to be connected to the grounded
conductor is clearly evident.

Exception: Terminal identification shall not be required for
devices that have a normal current rating of over 30 amperes,
other than polarized attachment plugs and polarized
receptacles for attachment plugs as required in 200.10(B).

(B) Receptacles, Plugs, and Connectors. Receptacles,
polarized attachment plugs, and cord connectors for plugs
and polarized plugs shall have the terminal intended for
connection to the grounded conductor identified as follows:

(1) Identification shall be by a metal or metal coating that
is substantially white in color or by the word white or
the letter ^located adjacent to the identified terminal.

70-44

2010 California Electrical Code

ARTICLE 2 1 - BRANCH CIRCUITS

210.4

(2) If the terminal is not visible, the conductor entrance
hole for the connection shall be colored white or
marked with the word white or the letter W.

FPN: See 250.126 for identification of wiring device
equipment grounding conductor terminals.

(C) Screw Shells. For devices with screw shells, the
terminal for the grounded conductor shall be the one
connected to the screw shell.

(D) Screw Shell Devices with Leads. For screw shell
devices with attached leads, the conductor attached to the
screw shell shall have a white or gray finish. The outer
finish of the other conductor shall be of a solid color that
will not be confused with the white or gray finish used to
identify the grounded conductor.

FPN: The color gray may have been used in the past as an
ungrounded conductor. Care should be taken when working
on existing systems.

(E) Appliances. Appliances that have a single-pole switch
or a single-pole overcurrent device in the line or any line-
connected screw shell lampholders, and that are to be
connected by (1) a permanent wiring method or (2) field-
installed attachment plugs and cords with three or more
wires (including the equipment grounding conductor), shall
have means to identify the terminal for the grounded circuit
conductor (if any).

200.11 Polarity of Connections. No grounded conductor
shall be attached to any terminal or lead so as to reverse the
designated polarity.

Bi*a;iich Circiiits^

I. General Provisions

210.1 Scope. This article covers branch circuits except for
branch circuits that supply only motor loads, which are
covered in Article 430. Provisions of this article and Article
430 apply to branch circuits with combination loads.

210.2 Other Articles for Specific-Purpose Branch
Circuits. Branch circuits shall comply with this article and
also with the applicable provisions of other articles of this
Code. The provisions for branch circuits supplying
equipment listed in Table 210.2 amend or supplement the
provisions in this article and shall apply to branch circuits
referred to therein.

210.3 Rating. Branch circuits recognized by this article
shall be rated in accordance with the maximum permitted
ampere rating or setting of the overcurrent device. The
rating for other than individual branch circuits shall be 15,
20, 30, 40, and 50 amperes. Where conductors of higher
ampacity are used for any reason, the ampere rating or
setting of the specified overcurrent device shall determine
the circuit rating.

Exception: Multioutlet branch circuits greater than 50
amperes shall be permitted to supply nonlighting outlet
loads on industrial premises where conditions of
maintenance and supervision ensure that only qualified
persons service the equipment

210.4 Multiwire Branch Circuits.

(A) General. Branch circuits recognized by this article
shall be permitted as multiwire circuits. A multiwire circuit
shall be permitted to be considered as multiple circuits. All
conductors ^JaN jmjBijyjffe ^m^:\s^<^ shall originate
from the same panelboard or similar distribution
equipment.

FPN: A 3 -phase, 4- wire, wye-connected power system used
to supply power to nonlinear loads may necessitate that the
power system design allow for the possibility of high
harmonic ^^^tf^S:ofiJi|eJg£^

(B) pis^ttii<^ri|g^^^^^ mtiltiwire feraach.citcui|
sliafi ' tfe : provide^ witli ^ m^wm tfisi^ will 's^nlimm'^i:

Exception No. 1: A multiwire branch circuit that supplies
only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the
multiwire branch circuit are opened simultaneously by the
branch-circuit overcurrent device.

FPN: See 300.13(B) for continuity of grounded conductor
on multiwire circuits.

Exception: ffe£^^E^^?!;^^rS^H^?J^(M»^^.^^/ MtPMib^ji
the circuit fJl^^^o^ a cable or mcewgy unique tp 'thi
''circuit ihaimake^ the grouping, obvi<>m:

2010 California Electrical Code

70™45

210.5

ARTICLE 210 - BRANCH CIRCUITS

Table 210.2 Specific-Purpose Branch Circuits

Equipment

Article

Section

Air-conditioning and

440.6,440.31,

refrigerating equipment

440.32

Audio signal processing,

640.8

amplification, and

reproduction equipment

Busways

368.17

Circuits and equipment

720

operating at less than 50 volts

Central heating equipment

422.12

other than fixed electric

space-heating equipment

Class 1, Class 2, and Class 3

725

remote-control, signaling,

and power-limited circuits

Cranes and hoists

610.42

Electric signs and outline

600.6

lighting

Electric welders

630

Blectnified JSck parjg|ig;^pace

* w.

Elevators, dumbwaiters,

escalators, moving walks,

wheelchair lifts, and

stairway chair lifts
Fire alarm systems 760

Fixed electric heating equipment

for pipelines and vessels
Fixed electric space-heating

equipment
Fixed outdoor electrical deicing

and snow-melting equipment
Information technology

equipment
Infrared lamp industrial

heating equipment

Induction and dielectric 665

heating equipment
Marinas and boatyards

Mobile homes, manufactured 550

homes, and mobile home

parks
Motion picture and television 530

studios and similar locations
Motors, motor circuits, and 430

controllers
Pipe organs

Recreational vehicles and 551

recreational vehicle parks
Switchboards and panelboards

Theaters, audience areas of

motion picture and television

studios, and similar locations
X-ray equipment

620.61

427.4
424.3
426.4
645.5
422.48, 424.3

555.19

650.7

408.52

520.41,520.52,
520.62

660.2,517.73

210.5 Identification for Branch Circuits.

(A) Grounded Conductor. The grounded conductor of a
branch circuit shall be identified in accordance with 200.6.

(B) Equipment Grounding Conductor. The equipment
grounding conductor shall be identified in accordance with
250.119.

(C) Ungrounded Conductors. Where the premises wiring
system has branch circuits suppHed from more than one
nominal voltage system, each ungrounded conductor of a
branch circuit shall be identified by pMseor line/^d
is>^tem; aL^iall: :term^ conaectioa; and sjjice ftbititsJ
The means of identification shall be permitted to be by
separate color coding, marking tape, tagging, or other
approved means. ;fte; mefe^^ "u^iztd. for conductors
originating withiri eachfcraihch-citcu skmlat
branch-oircui^^^^ equipment shall be documented
in a mamer thaH^^^^^ shall be permanently
posted at each branch-circuit panelboard or similar branch-
circuit distribution equipment.

210.6 Branch-Circuit Voltage Limitations. The nominal
voltage of branch circuits shall not exceed the values
permitted by 210.6(A) through (E).

(A) Occupancy Limitation, hi dwelling units and guest
rooms or guest suites of hotels, motels, and similar
occupancies, the voltage shall not exceed 120 volts, nominal,
between conductors that supply the terminals of the following:

(1) Luminaires

(2) Cord-and-plug-connected loads 1440 volt-amperes,
nominal, or less or less than % hp

(B) 120 Volts Between Conductors. Circuits not exceeding
120 volts, nominal, between conductors shall be permitted to
supply the following:

(1) The terminals of lampholders apphed within their
voltage ratings

(2) Auxiliary equipment of electric-discharge lamps

(3) Cord-and-plug-connected or permanently connected
utilization equipment

(C) 277 Volts to Ground. Circuits exceeding 120 volts,
nominal, between conductors and not exceeding 277 volts,
nominal, to ground shall be permitted to supply the
following:

(1) Listed electric-discharge luminaires

(2) Listed incandescent luminaires, where supplied at 120
volts or less from the output of a stepdown
autotransformer that is an integral component of the
luminaire and the outer shell terminal is electrically
connected to a grounded conductor of the branch circuit

70^6

2010 California Electrical Code

ARTICLE 210 - BRANCH CIRCUITS

210.8

(3) Luminaires equipped with mogul-base screw shell
lampholders

(4) Lampholders, other than the screw shell type, applied
within their voltage ratings

(5) Auxiliary equipment of electric-discharge lamps

(6) Cord-and-plug-connected or permanently connected
utilization equipment

(D) 600 Volts Between Conductors. Circuits exceeding
277 volts, nominal, to ground and not exceeding 600 volts,
nominal, between conductors shall be permitted to supply
the following:

(1) The auxiliary equipment of electric-discharge lamps
mounted in permanently installed luminaires where the
luminaires are mounted in accordance with one of the

following:

a. Not less than a height of 6.7 m (22 ft) on poles or

similar structures for the illumination of outdoor
areas such as highways, roads, bridges, athletic
fields, or parking lots

b. Not less than a height of 5.5 m (18 ft) on other

structures such as tunnels

(2) Cord-and-plug-connected or permanently connected
utilization equipment other than luminaires

l%^-^§mmkm |c^rate'd; teU^t .tfii£|

§^^^ isblatipn J)^!^^ the 4e power souro^ " aii3

FPN: See 410.l3| for auxiliary equipment limitations.

Exception No. I to (B), (C), and (D): For lampholders of
infrared industrial heating appliances as provided in

422.14.

Exception No. 2 to (B), (C), and (D): For railway
properties as described in 110.19.

(E) Over 600 Volts Between Conductors. Circuits
exceeding 600 volts, nominal, between conductors shall be
permitted to supply utilization equipment in installations
where conditions of maintenance and supervision ensure
that only qualified persons service the installation.

210.7 Branch-Circuit Requirements tor ;Deyic^

(A) Receptacle Outlet Location. Receptacle outlets shall
be located in branch circuits in accordance with Part III of
Article 210.

(B) Multiple Branch Circuits. Where two or more branch
circuits supply devices or equipment on the same yoke, a

means to simultaneously disconnect the ungrounded
conductors supplying those devices shall be provided at the
point at which the branch circuits originate.

210.8 Ground-Fault Circuit-Interrupter Protection for
Personnel.

FPN: See 215.9 for ground-fault circuit-interrupter
protection for personnel on feeders.

(A) Dwelling Units. All 125-volt, single-phase, 15- and
20-ampere receptacles installed in the locations specified in
(1) through (8) shall have ground- fault circuit-interrupter
protection for personnel.

(1) Bathrooms

(2) Garages, and also accessory buildings that have a floor
located at or below grade level not intended as
habitable rooms and limited to storage areas, work
areas, and areas of similar use

(3) Outdoors

Exception to (3): Receptacles that are not readily
accessible and are supplied by a dedicated branch circuit
for electric snow-melting or deicing equipment shall be
permitted to be installed in accordance with 426.28.

(4) Crawl spaces — at or below grade level

(5) Unfinished basements — for purposes of this section,
unfinished basements are defined as portions or areas
of the basement not intended as habitable rooms and
limited to storage areas, work areas, and the like

Exception to (5): A receptacle supplying only a
permanently installed fire alarm or burglar alarm system
shall not be required to have ground-fault circuit-
interrupter protection.

pPN: Sed^ 760)1 i(F) and 760.iI2i(B) fik' powrjiiipply
requi^menk for fire alarm systc^J

Receptacles installed under the exception to
210.8(A)(5) shall not be considered as meeting the
requirements of 210.52(G).

(6) Kitchens — where the receptacles are installed to serve
the countertop surfaces

(7) Laundry, utility, and wet bar sinks — where the
receptacles are installed within 1.8 m (6 ft) of the
outside edge of the sink

(8) Boathouses

(B) Other Than Dwelling Units. All 125-voh, single-
phase, 15- and 20-ampere receptacles installed in the
locations specified in (1) through (5) shall have ground-
fault circuit-interrupter protection for personnel:

(1) Bathrooms

(2) Kitchegg

(3) Rooftops

(4) iOffiSrl

2010 California Electrical Code

70^^7

210.9

ARTICLE 210 - BRANCH CIRCUITS

Exception No. 1 to (3) and (4): Receptacles that are not
readily accessible and are supplied from a dedicated
branch circuit for electric snow-melting or deicing
equipment shall be permitted to be installed mthoulGFCJ.
protectiml

lBxceplion{Na:'f£ 'ip'- 0):-'0: ifidusMdl '^stMUhmerits only;.

'asmre'(i_ eqmpfnent' M9^p4}f^K,. !^^)^^^^MK: M^M^^Hj(i
specified in "590j^'(B)J2}^ shafl be permitted fp^ only those
receptacle outlets used to supply equipment that, would
create a greater hazard ^ power 'is interrupted or having d,
design thahs not compatible with GFCt prqtectioni

(5) Siiiks — where, rece|)tacles are installed within 1.8 m
(6 ft) pf the outride edge^^ sidk.^

Exception N& I:,J<>_(5}:-^\ In if^mtrial laboratories,
receptacles ^^ used to supply equipm^^ removal of

power would inp;pdHce a greater hazard shall be permitted

to berins tailed yf^MputOFCl^

Exception No '2/tq (5): :fPpr receptacles located in

care areas of he^^^ than those covered

installed in dwelling unit locations.

210.9 Circuits Derived from Autotransformers. Branch
circuits shall not be derived from autotransformers unless
the circuit supplied has a grounded conductor that is
electrically connected to a grounded conductor of the
system supplying the autotransformer.

Exception No. I: An autotransformer shall be permitted
without the connection to a grounded conductor where
transforming from a nominal 208 volts to a nominal 240-
volt supply or similarly from 240 volts to 208 volts.

Exception No. 2: In industrial occupancies, where
conditions of maintenance and supervision ensure that only
qualified persons service the installation, autotransformers
shall be permitted to supply nominal 600-volt loads from
nominal 480-volt systems, and 480-volt loads from nominal
600-volt systems, without the connection to a similar
grounded conductor.

210.10 Ungrounded Conductors Tapped from Grounded
Systems. Two-wire dc circuits and ac circuits of two or
more ungrounded conductors shall be permitted to be tapped
from the ungrounded conductors of circuits that have a
grounded neutral conductor. Switching devices in each
tapped circuit shall have a pole in each ungrounded
conductor. All poles of multipole switching devices shall

manually switch together where such switching devices also
serve as a disconnecting means as required by the following:

(1) 4 10. H for double-pole switched lampholders

(2) 410.|^(B) for electric-discharge lamp auxiliary

equipment switching devices

(3) 422.31(B) for an apphance

(4) 424.20 for a fixed electric space-heating unit

(5) 426.51 for electric deicing and snow-melting equipment

(6) 430.85 for a motor controller

(7) 430.103 for a motor

210.11 Branch Circuits Required. Branch circuits for
hghting and for apphances, including motor-operated
appliances, shall be provided to supply the loads calculated
in accordance with 220.10. In addition, branch circuits
shall be provided for specific loads not covered by 220.10
where required elsewhere in this Code and for dwelling
unit loads as specified in 210.1 1(C).

(A) Number of Branch Circuits. The minimum number
of branch circuits shall be determined from the total
calculated load and the size or rating of the circuits used. In
all installations, the number of circuits shall be sufficient to
supply the load served. In no case shall the load on any
circuit exceed the maximum specified by 220.18.

(B) Load Evenly Proportioned Among Branch Circuits,

Where the load is calculated on the basis of volt-amperes
per square meter or per square foot, the wiring system up to
and including the branch-circuit panelboard(s) shall be
provided to serve not less than the calculated load. This
load shall be evenly proportioned among multioutlet
branch circuits within the panelboard(s). Branch-circuit
overcurrent devices and circuits shall be required to be
installed only to serve the connected load.

(1) Small-Appliance Branch Circuits. In addition to the
number of branch circuits required by other parts of this section,
two or more 20-ampere small-appliance branch circuits shall be
provided for all receptacle outlets specified by 210.52(B).

(2) Laundry Branch Circuits. In addition to the number
of branch circuits required by other parts of this section, at
least one additional 20-ampere branch circuit shall be
provided to supply the laundry receptacle outlet(s) required
by 210.52(F). This circuit shall have no other outlets.

(3) Bathroom Branch Circuits. In addition to the number
of branch circuits required by other parts of this section, at
least one 20-ampere branch circuit shall be provided to
supply bathroom receptacle outlet(s). Such circuits shall
have no other outlets.

70-48

2010 California Electrical Code

ARTICLE 210 - BRANCH CIRCUITS

210.19

Exception: Where the 20-ampere circuit supplies a single
bathroom, outlets for other equipment within the same
bathroom shall be permitted to be supplied in accordance
with 210.23(A)(1) and (A)(2).

FPN: See Examples Dl(a), Dl(b), D2(b), and D4(a) in
Annex D.

210.12 Arc-Fault Circuit-Interrupter Protection.

(A) Definition: Arc-Fault Circuit Interrupter (AFCI). A

device intended to provide protection from the effects of
arc faults by recognizing characteristics unique to arcing
and by functioning to de-energize the circuit when an arc
fault is detected.

(B) DwelUng fSite. All 120-volt, single phase, 15- and 20-
ampere branch circuits supplying outlets installed in dwelling
unit jfami V. rooms, dmiug rooms, living rooms, parlors]
ibrari^^^sJ&etooms^^ recr^ti^T<>oi^,^lose^^
SkHMyiL&:^?(M^(^,.^^ shall be protected by a
listed arc-fault circuit interrupter, combination-type, installed
to provide protection of the branch circuit.

llSjSiESl FoJ" information on t5T>es of arc-fault circuit
interrupters, see UL 1699-1999, Standard for Arc-Fault
Circuit Interrupters .

WM:S>^^M^M^MM and 760.121(1) for power-
supply requirements for fire alarm systems.

Exception No. 1: 'Where^RMQlMQMl^

^et^^Su^fmdjunAion-' boxes- m\ tj^i^MpSi^A^i^P^^M^^
%e:3f:dricMcifhJ0rie(^^

^ombJmii§h:]iF€I dtjh^j§rst outlet 'toJiTQ^jde prdte^tfp^^t

Exception No. 2: 'Where^^i hramh^c^^

'^fyslem^J^tdled^^ ;with ;^ 76pJl(Bjj, and

kirmhred .'^abh^ type' AC, meeting, the requirements of
WiOjlM, \viih metal qutlet and jmctian bpx^Sjl Ap'Ct
''pmhckod.shaUhe^ to be^pmiiiedl

210.18 Guest Rooms and Guest Suites. Guest rooms and
guest suites that are provided with permanent provisions
for cooking shall have branch circuits installed to meet the
rules for dwelling units.

II. Branch-Circuit Ratings

210.19 Conductors — Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.

(1) General Branch-circuit conductors shall have an

ampacity not less than the maximum load to be served. Where
a branch circuit supplies continuous loads or any combination
of continuous and noncontinuous loads, the minimum branch-
circuit conductor size, before the application of any
adjustment or correction factors, shall have an allowable
ampacity not less than the noncontinuous load plus 125
percent of the continuous load. Exception No. 1: Where the
assembly, including the overcurrent devices protecting the
branch circuit(s), is listed for operation at 100 percent of its
rating, the allowable ampacity of the branch circuit
conductors shall be permitted to be not less than the sum of
the continuous load plus the noncontinuous load.
Exception No, 2: XStpu^4^;i^^fi^^
, g^ei6i0 p[€^-^^^ 'be

FPN No. 1: See 3 10.15 for ampacity ratings of conductors.
FPN No. 2: See Part II of Article 430 for minimum rating of
motor branch-circuit conductors.

FPN No. 3: See 310.10 for temperature limitation of
conductors.

FPN No. 4: Conductors for branch circuits as defined in
Article 100, sized to prevent a voltage drop exceeding 3
percent at the farthest outlet of power, heating, and lighting
loads, or combinations of such loads, and where the
maximum total voltage drop on both feeders and branch
circuits to the farthest outlet does not exceed 5 percent,
provide reasonable efficiency of operation. See FPN No. 2 of
215.2(A)(3) for voltage drop on feeder conductors.

(2) Multioutlet Branch Circuits. Conductors of branch
circuits supplying more than one receptacle for cord-and-
plug-connected portable loads shall have an ampacity of not
less than the rating of the branch circuit.

(3) Household Ranges and Cooking Appliances. Branch-
circuit conductors supplying household ranges, wall-
mounted ovens, counter-mounted cooking units, and other
household cooking appliances shall have an ampacity not
less than the rating of the branch circuit and not less than the
maximum load to be served. For ranges of %Va kW or more
rating, the minimum branch-circuit rating shall be 40
amperes.

Exception No. 1: Conductors p^^|?^]§ig»i= «■ SQ-ampete
W0f0^{;icim4& supplying electric ranges, wall-mounted
electric ovens, and counter-mounted electric cooking units
shall have an ampacity of not less than 20 d^^af^ and shall
be sufficient for the load to be served. These tap conductors
include any conductors that are apart of the leads supplied
with the appliance that are smaller than the branch-circuit
conductors. The taps shall not be longer than necessary for
servicing the appliance.

2010 California Electrical Code

70-49

210,20

ARTICLE 210 - BRANCH CIRCUITS

Exception No. 2: The neutral conductor of a 3-wire branch
circuit supplying a household electric range, a wall-mounted
oven, or a counter-mounted cooking unit shall be permitted
to be smaller than the ungrounded conductors where the
maximum demand of a range of8V4-kW or more rating has
been calculated according to Column C of Table 220.55, but
such conductor shall have an ampacity of not less than 70
percent of the branch-circuit rating and shall not be smaller
thanlOAWG.

(4) Other Loads. Branch-circuit conductors that supply
loads other than those specified in 210.2 and other than
cooking appliances as covered in 210.19(A)(3) shall have an
ampacity sufficient for the loads served and shall not be
smaller than

Exception No. 1 : Tap conductors shall have an ampacity
sufficient for the load served. In addition, they shall have
an ampacity of not less than 15 for circuits rated less than
40 amperes and not less than 20 for circuits rated at 40 or
50 amperes and only where these tap conductors supply
any of the following loads:

(a) Individual lampholders or luminaires with taps
extending not longer than 450 mm (18 in.) beyond any
portion of the lampholder or luminaire.

(b) A luminaire having tap conductors as provided in
410.117.

(d) Infrared lamp industrial heating appliances.

(e) Nonheating leads of deicing and snow-melting
cables and mats.

Exception No. 2: Fixture wires and flexible cords shall be
permitted to be smaller than 14 A WG as permitted by 240.5.

(B) Branch Circuits Over 600 Volts. The ampacity of
conductors shall be in accordance with 310.15 and 310,60,
as applicable. Branch-circuit conductors over 600 volts
shall be sized in accordance with 210.19(B)(1) or (B)(2),

(1) General. The ampacity of branch-circuit conductors
shall not be less than 125 percent of the designed potential
load of utilization equipment that will be operated
simultaneously.

(2) Supervised Installations. For supervised installations,
branch-circuit conductor sizing shall be permitted to be
determined by qualified persons under engineering
supervision. Supervised installations are defined as those
portions of a facility where both of the following
conditions are met:

(1) Conditions of design and installation are provided
under engineering supervision.

(2) Qualified persons with documented training and
experience in over 600-voh systems provide
maintenance, monitoring, and servicing of the system.

210.20 Overcurrent Protection. Branch-circuit
conductors and equipment shall be protected by
overcurrent protective devices that have a rating or setting
that complies with 210.20(A) through (D).

(A) Continuous and Noncontinuous Loads. Where a
branch circuit supplies continuous loads or any combination
of continuous and noncontinuous loads, the rating of the
overcurrent device shall not be less than the noncontinuous
load plus 125 percent of the continuous load.

Exception: Where the assembly, including the overcurrent
devices protecting the branch circuit(s), is listed for
operation at 100 percent of its rating, the ampere rating of
the overcurrent device shall be permitted to be not less
than the sum of the continuous load plus the noncontinuous
load.

(B) Conductor Protection. Conductors shall be protected
in accordance with 240.4. Flexible cords and fixture wires
shall be protected in accordance with 240.5.

(C) Equipment. The rating or setting of the overcurrent
protective device shall not exceed that specified in the
applicable articles referenced in Table 240.3 for equipment.

(D) Outlet Devices. The rating or setting shall not exceed
that specified in 210.21 for outlet devices.

210.21 Outlet Devices. Outlet devices shall have an
ampere rating that is not less than the load to be served and
shall comply with 210.21(A) and (B).

(A) Lampholders. Where connected to a branch circuit
having a rating in excess of 20 amperes, lampholders shall
be of the heavy-duty type. A heavy-duty lampholder shall
have a rating of not less than 660 watts if of the admedium
type, or not less than 750 watts if of any other type.

(B) Receptacles.

(1) Single Receptacle on an Individual Branch Circuit.

A single receptacle installed on an individual branch circuit
shall have an ampere rating not less than that of the branch
circuit.

Exception No. 1: A receptacle installed in accordance with
430.81(B).

Exception No. 2: A receptacle installed exclusively for the
use of a cord-and-plug-connected arc welder shall be
permitted to have an ampere rating not less than the
minimum branch-circuit conductor ampacity determined by
630.11 (A) for arc welders.

FPN: See the definition of receptacle in Article 100.

(2) Total Cord-and-Plug-Connected Load. Where connected
to a branch circuit supplying two or more receptacles or
outlets, a receptacle shall not supply a total cord-and-
plug-connected load in excess of the maximum specified
in Table 210.21(B)(2).

70-50

2010 California Electrical Code

ARTICLE 210- BRANCH CIRCUITS

210.25

Table 210.21(B)(2)

Maximum Cord-and-Plug-Connected

Load to Receptacle

Circuit Rating

Receptacle Rating

Maximum Load

(Amperes)

15 or 20

(3) Receptacle Ratings. Where connected to a branch circuit
supplying two or more receptacles or outlets, receptacle
ratings shall conform to the values listed in Table
210.21(B)(3), or where larger than 50 amperes, the receptacle
rating shall not be less than the branch-circuit rating.

Exception No. 1: Receptacles for one or more cord-and-
plug-connected arc welders shall be permitted to have
ampere ratings not less than the minimum branch-circuit
conductor' ampacity permitted by 630.11(A) or (B) as
applicable for arc welders.

Exception No. 2: The ampere rating of a receptacle
installed for electric discharge lighting shall be permitted
to be based on 410.62(C).

Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits

Circuit Rating

Receptacle Rating

(Amperes)

Not over 1 5

15 or 20

40 or 50

(4) Range Receptacle Rating. The ampere rating of a
range receptacle shall be permitted to be based on a single
range demand load as specified in Table 220.55.

210.23 Permissible Loads. In no case shall the load
exceed the branch-circuit ampere rating. An individual
branch circuit shall be permitted to supply any load for
which it is rated. A branch circuit supplying two or more
outlets or receptacles shall supply only the loads specified
according to its size as specified in 210.23(A) through (D)
and as summarized in 210.24 and Table 210.24.

(A) 15- and 20-Ampere Branch Circuits. A 15- or 20-

ampere branch circuit shall be permitted to supply lighting
units or other utilization equipment, or a combination of
both, and shall comply with 210.23(A)(1) and (A)(2).

Exception: The small-appliance branch circuits, laundry
branch circuits, and bathroom branch circuits required in
a dwelling unit(s) by 210.11(C)(1), (C)(2), and (C)(3) shall
supply only the receptacle outlets specified in that section.

(1) Cord-and-Plug-Connected Equipment Not Fastened
in Place. The rating of any one cord-and-plug-connected
utilization equipment not fastened in place shall not exceed
80 percent of the branch-circuit ampere rating.

(2) Utilization Equipment Fastened in Place. The total rating
of utilization equipment fastened in place, other than luminaires,
shall not exceed 50 percent of the branch-circuit ampere rating
where lighting units, cord-and-plug-connected utilization
equipment not fastened in place, or both, are also supplied.

(B) 30-Ampere Branch Circuits. A 30-ampere branch
circuit. shall be permitted to supply fixed lighting units with
heavy-duty lampholders in other than a dwelling unit(s) or
utilization equipment in any occupancy. A rating of any
one cord-and-plug-connected utilization equipment shall
not exceed 80 percent of the branch-circuit ampere rating.

(C) 40- and 50-Ampere Branch Circuits. A 40- or 50-
ampere branch circuit shall be permitted to supply cooking
appliances that are fastened in place in any occupancy. In
other than dwelling units, such circuits shall be permitted to
supply fixed lighting units with heavy-duty lampholders,
infrared heating units, or other utilization equipment.

(D) Branch Circuits Larger Than 50 Amperes. Branch
circuits larger than 50 amperes shall supply only
nonlighting outlet loads.

210.24 Branch-Circuit Requirements — Summary. The

requirements for circuits that have two or more outlets or
receptacles, other than the receptacle circuits of
210.11(C)(1) and (C)(2), are summarized in Table 210.24.
This table provides only a summary of minimum
requirements. See 210.19, 210.20, and 210.21 for the
specific requirements applying to branch circuits.

210.25 Branch Circuits ji^ufld^^^ Than
One Occupancy.

(A) BweUlag Unit Branch Circuit!^. Branch circuits in each
dwelling ]unjt shall supply only loads within that dwelling

unit or loads associated only with that dwelling unit.

IB) Go^inrnpn j^rea jBraiicfe^j O Branch circuits

required for the purpose of lighting, central alarm, signal,
communications, or otherjieed[s for public or common areas
of ajtwo-family jdweiling, j^multifamjlY:d^ or a multi-

jc^cupancy building shall not be supplied from equipment
that supplies an individual dwelling unit or tenagt space.

2010 California Electrical Code

70-51

210.50

ARTICLE 210 - BRANCH CIRCUITS

Table 210.24 Summary of Branch-Circuit Requirements

Circuit Rating

15 A

20 A

30 A

40 A

50 A

Conductors (min. size):

Circuit wires
Taps
Fixture wires and cords —

see 240.5

8
12

Overcurrent Protection

15 A

20 A

30 A

40 A

50 A

Outlet devices:
Lampholders permitted

Receptacle rating

Any type
15 max. A

Any type

15 or 20 A

Heavy duty
30 A

Heavy duty
40 or 50 A

Heavy duty
50 A

Maximum Load

15 A

20 A

30 A

40 A

50 A

Permissible load

See 210.23(A)

See 210.23(B)

See 210.23(C)

These gauges are for copper conductors.

For receptacle rating of cord-connected electric-discharge luminaires (hghting fixtures), see 410.30(C).

A
C
A
C
A
C
A

III. Required Outlets

210.50 General. Receptacle outlets shall be installed as

specified in 210.52 through 210.63.

(A) Cord Pendants. A cord connector that is supplied by a
permanently connected cord pendant shall be considered a
receptacle outlet.

(B) Cord Connections. A receptacle outlet shall be installed
wherever flexible cords with attachment plugs are used. Where
flexible cords are permitted to be permanently connected,
receptacles shall be permitted to be omitted for such cords.

(C) Appliance |leceptocle Outlets. Appliance receptacle
outlets installed in a dweUing unit for specific appliances,
such as laundry equipment, shall be installed within 1.8 m
(6 ft) of the intended location of the appliance.

(D) fDPHJ Commissary Service Outlet A commissary which
services food preparation units shall provide one outlet for each
vehicle requiring electrical power for mechanical refrigeration,

(E) [DPH w/ exceptions] Installation Height The center of 15-,
20-, and 30-ampere receptacle outlets required by sections 210-
52(A), (B), and (C) shall be installed not less than 12 inches
above the floor or working platform.

Exception No. 1: Receptacle outlets installed as part of
permanently installed baseboard heaters are exempt.
Exception No. 2: Required receptacle outlets shall be permitted in
floors when adjacent to sliding panels or walls.
Exception No. 3: Baseboard electrical outlets used in relocatable
partitions, window walls or other electrical convenience floor
outlets are not subject to the minimum height requirements.
210.52 Dwelling Unit Receptacle Outlets. This section
provides requirements for 125-volt, 15- and 20-ampere
receptacle outlets. Jhejreceptade^ required by this section
shall be in addition to anj; recepjtacle that is:

(2) |Gpiitr6iled:';by :' a - ; -wall swife;}i^ in ; &cprto wltfi

(3) tocated \Htliiii cabine^^^ _

(4) ^Located more thanj.7^^ (SJ/^ft) abqv^ th^ftol?

Permanently installed electric baseboard heaters equipped

with factory-installed receptacle outlets or outlets provided as
a separate assembly by the manufacturer shall be permitted as
the required outlet or outlets for the wall space utilized by such
permanently installed heaters. Such receptacle outlets shall not
be connected to the heater circuits.

FPN: Listed baseboard heaters include instructions that may
not permit their installation below receptacle outlets.

(A) General Provisions, In every kitchen, family room, dining
room, living room, parlor, library, den, sunroom, bedroom,
recreation room, or similar room or area of dwelling units,
receptacle outlets shall be installed in accordance with the
general provisions specified in 210.52(A)(1) through (A)(3).

(1) Spacing. Receptacles shall be installed such that no
point measured horizontally along the floor line in any wall
space is more than 1.8 m (6 ft) from a receptacle outlet.

(2) Wall Space. As used in this section, a wall space shall
include the following:

(1) Any space 600 mm (2 ft) or more in width (including
space measured around comers) and unbroken along the
floor line by doorways, fireplaces, and similar openings

(2) The space occupied by fixed panels in exterior walls,
excluding sliding panels

(3) The space afforded by fixed room dividers such as
freestanding bar-type counters or railings

(3) Floor Receptacles. Receptacle outlets in floors shall
not be counted as part of the required number of receptacle
outlets unless located within 450 mm (18 in.) of the wall.

(B) Small Appliances.

(1) Receptacle Outlets Served. In the kitchen, pantry,
breakfast room, dining room, or similar area of a dwelling
unit, the two or more 20-ampere small-appliance branch
circuits required by 210.11(C)(1) shall serve all wall and
floor receptacle outlets covered by 210.52(A), all
countertop outlets covered by 210.52(C), and receptacle
outlets for refrigeration equipment.

70-52

2010 California Electrical Code

ARTICLE 210 - BRANCH CIRCUITS

210.52

Exception No. 1: In addition to the required receptacles
specified by 210.52, switched receptacles supplied from a
general-purpose branch circuit as defined in 210.70(A)(1),
Exception No. 1, shall be permitted.

Exception No. 2: The receptacle outlet for refrigeration
equipment shall be permitted to be supplied from an
individual branch circuit rated 15 amperes or greater.

(2) No Other Outlets. The two or more small-appliance
branch circuits specified in 210.52(B)(1) shall have no
other outlets.

Exception No. 1: A receptacle installed solely for the
electrical supply to and support of an electric clock in any
of the rooms specified in 210.52(B)(1).

Exception No. 2: Receptacles installed to provide power
for supplemental equipment and lighting on gasfired
ranges, ovens, or counter-mounted cooking units.

(3) Kitchen Receptacle Requirements. Receptacles
installed in a kitchen to serve countertop surfaces shall be
supplied by not fewer than two small-appliance branch
circuits, either or both of which shall also be permitted to
supply receptacle outlets in the same kitchen and in other
rooms specified in 210.52(B)(1). Additional small-
appliance branch circuits shall be permitted to supply
receptacle outlets in the kitchen and other rooms specified
in 210.52(B)(1). No small-appliance branch circuit shall
serve more than one kitchen.

(C) Countertops. In kitchens, ^^^^S^^^^^^M^mI
BjBjmg rooms, aiid; siniilajc areas of dwelling units,
receptacle outlets for countertop spaces shall be installed in
accordance with 210.52(C)(1) through (C)(5).

^^ iWher^ a range, ;cou|lt^r-ii^p|tM \i

kf^eStetoBIand'^^^

jto|'j

^bemndi ji^ ,,^i#i';;'M^^^i:feL^^Ml^

^uiitelppl ^p^'^^iafe J two ' ' si^imt^'; ' ,goi5Wqp" siages ; "fi
defined mM^4%i£&r &?ii,„?^^^l?.i<M^^
iqondply Mftt&;^plcabie t^m^ms^M'^^Mi®.

(1) Wall jEoupteit^i Spaces. A receptacle outlet shall be
installed at each wall ^W§^^ space that is 300 mm (12
in.) or wider. Receptacle outlets shall be installed so that no
point along the wall line is more than 600 mm (24 in.)
measured horizontally from a receptacle outlet in that space.

Exception: Receptacle outlets shall not be required on a

wall directly behind a range, ^^pMnter^momh^^

or sink in the installation described in W^K^iMSi^MI^MQi

Outlet within
'^0mm(24in.r

Space exempt from wall
line if X< 300 mm (12 in.)

Outlet within
600 mm (24 inj^

\ t

r 'V

V J ^ J , ^j^^„^^ J

Range^ counter-mounted cooking unit extending
from face of counter

Space exempt from wall line
If X< 450 mm (18 in.)

Oullet within
600 mm

(24 in.)

-Outlet within 600 mm (24 in.) -

Ranqe, counter-mounted cookinq unit mounted in corner

Figure 210.52(C)(1) Determination of Area Behind a Range,
or Counter-Mounted Cooking Unit or Sink.

(2) Island ^oujjitfftgjl Spaces. At least one receptacle
shall be installed at each island 'm^ttip^ space with a
long dimension of 600 mm (24 in.) or greater and a short
dimension of 300 mm (12 in.) or greater.

(3) Peninsular ^Qiijitejlgii Spaces. At least one receptacle
outlet shall be installed at, each peninsular countertop space
with a long dimension of 600 mm (24 in.) or greater and a
short dimension of 300 mm (12 m.) or greater. A peninsular
countertop is measured from the connecting edge.

(4) Separate Spaces. Countertop spaces separated by
rangetops, refrigerators, or sinks shall be considered as
separate countertop spaces in applying the requirements of
210.52(C)(1), (C)(2), and (C)(3).

(5) Receptacle Outlet Location. Receptacle outlets shall
be located above, but not more than 500 mm (20 in.) above,
the countertop. Receptacle outlets rendered not readily

2010 California Electrical Code

70-53

210.60

ARTICLE 210 - BRANCH CIRCUITS

accessible by appliances fastened in place, appliance
garages, sinks, or rangetops as covered in 210.52(C)(1),
Exception, or appliances occupying dedicated space shall
not be considered as these required outlets.

Exception to (5): To comply with the conditions specified in
(1) or (2), receptacle outlets shall be permitted to be mounted
not more than 300 mm (12 in.) below the countertop.
Receptacles mounted below a countertop in accordance with
this exception shall not be located where the countertop
extends more than 150 mm (6 in.) beyond its support base.

(1) Construction fi)r the physically impaired

(2) On island and peninsular countertops where the
countertop is flat across its entire surface (no
backsplashes, dividers, etc.) and there are no means to
mount a receptacle within 500 mm (20 in.) above the
countertop, such as an overhead cabinet

(D) Bathrooms. In dwelling units, at least one receptacle
outlet shall be installed in bathrooms within 900 mm (3 ft) of
the outside edge of each basin. The receptacle outlet shall be
located on a wall or partition that is adjacent to the basin or
basin countertop, ox instiled on tbe side or face of the basin
Eabinet not more than 300 mm (12 in.) below tiie cpratertop*;

(E) Outdoor Outlets. Outdoor teceptacle outlets shall be
installed in accordanqe with (E)(1) tlffough (E){3}. [See

liiMm)-] "^ 2""

(1) One-Famiiy and TwO'Faniiiy Dwellii5^3 For a one-
family dwelling and each unit of a two-family dwelling that
is at grade level, at least one receptacle outlet accessible
^^le standing at grade level and located not more than 2.0
m {6V2 ft) above grade shall be installed at the front and
back of the dwelling.

i^lJJNfiilrtlafldJX For each dwelling unit of a

multifamily dwelling where the dwelling unit is located at
grade level and provided with individual exterior
entrance/egress, at least one receptacle outlet accessible
from grade level and not more than 2.0 m {6V2 ft) above
grade shall be installed.

(5) ■ BalcoiiieSj^Decli^^ Bdcqmes^^ d^^ks, and

poaches that are acj^ssiW^^ inside &/dw^^^

Ifoli have at least ori^

perimetei of the bal^y, B^ck^ or porcii. The red^y^t^le
;$JW1; BOt^be locjrted;'Hra;e;&a§, 2.0 mX6Y2.:'M:^^oye^&€f
balcony, deck, or porch surfaced

Exception to (3): Balconies, decks, or porches with a

usable area of less than 1.86 m^ (20 ft^) are not required
to have a receptacle installed.

(F) Laundry Areas. In dwelling units, at least one
receptacle outlet shall be installed for the laundry.

Exception No. 1: In a dwelling unit that is an apartment or
living area in a multifamily building where laundry
facilities are provided on the premises and are available to
all building occupants, a laundry receptacle shall not be
required.

Exception No. 2: In other than one-family dwellings where
laundry facilities are not to be installed or permitted, a
laundry receptacle shall not be required.

(G) Basements and Garages. For a one-family dwelling,
|he fpllowihg prbvisiois shall apply:

(1) At least one receptacle outlet, |ii:Mditi£ri2t£;;thds^^

l^cific ei^urgiSliitT shall be installed in each
basement, in each attached garage, and in each
detached garage with electric power.

(2) Where a portion of the basement is finished into one or
more habitable rooms, each separate unfinished
portion shall have a receptacle outlet installed in
accordance with this section.

(H) Hallways. In dwelling units, hallways of 3.0 m (10 ft)
or more in length shall have at least one receptacle outlet.

As used in this subsection, the hall length shall be
considered the length along the centerline of the hall
without passing through a doorway.

210.60 Guest Rooms, Guest Suites, t^'iiTM^^^h^h^.
SlmMLSccttpaii^

(A) General. Guest rooms or guest suites in hotels, motels,

sleepmg tqop:^ to and similar occupancies

shall have receptacle outlets installed in accordance with
210.52(A) and 210.52(D). Guest rooms or guest suites
provided with permanent provisions for cooking shall have
receptacle outlets installed in accordance with all of the
applicable rules in 210.52.

(B) Receptacle Placement. In applying the provisions of
210.52(A), the total number of receptacle outlets shall not
be less than the minimum number that would comply with
the provisions of that section. These receptacle outlets shall
be permitted to be located conveniently for permanent
ftirniture layout. At least two receptacle outlets shall be
readily accessible. Where receptacles are installed behind
the bed, the receptacle shall be located to prevent the bed
from contacting any attachment plug that may be installed
or the receptacle shall be provided with a suitable guard.

•

70-54

2010 California Electrical Code

ARTICLE 2 1 5 - FEEDERS

215.1

210.62 Show Windows. At least one receptacle outlet
shall be installed ^^^^iOm^

show window for each 3.7 linear m (12 linear ft) or major
fraction thereof of show window area measured
horizontally at its maximum width.

210.63 Heating, Air-Conditioning, and Refrigeration
Equipment Outlet. A 125-volt, single-phase, 15- or 20-
ampere-rated receptacle outlet shall be installed at an
accessible location for the servicing of heating, air-
conditioning, and refrigeration equipment. The receptacle
shall be located on the same level and within 7.5 m (25 ft)
of the heating, air-conditioning, ^nd refrigeration
equipment. The receptacle outlet shall not be connected to
the load side of the equipment disconnecting means.

Exception: A receptacle outlet shall not be required at
one- and two-family dwellings for the service of
evaporative coolers.

FPN: See 210.8 for ground- fault circuit-interrupter
requirements.

210.70 Lighting Outlets Required. Lighting outlets shall
be installed where specified in 210.70(A), (B), and (C).

(A) Dwelling Units. In dwelling units, lighting outlets shall
be installed in accordance with 210.70(A)(1), (A)(2), and
(A)(3).

(1) Habitable Rooms. At least one wall switch-controlled
lighting outlet shall be installed in every habitable room
and bathroom.

Exception No. 1: In other than kitchens and bathrooms,
one or more receptacles controlled by a wall switch shall
be permitted in lieu of lighting outlets.

Exception No. 2: Lighting outlets shall be permitted to be
controlled by occupancy sensors that are (I) in addition to
wall switches or (2) located at a customary wall switch
location and equipped with a manual override that will
allow the sensor to function as a wall switch.

(2) Additional Locations. Additional lighting outlets shall be
installed in accordance with (A)(2)(a), (A)(2)(b), and (A)(2)(c).

(a) At least one wall switch-controlled lighting outlet shall
be installed in hallways, stairways, attached garages, and
detached garages with electric power.

(b) For dwelling units, attached garages, and detached
garages with electric power, at least one wall sv^tch-controlled
lighting outlet shall be installed to provide illumination on the
exterior side of outdoor entrances or exits with grade level
access. A vehicle door in a garage shall not be considered as an
outdoor entrance or exit.

(c) Where one or more lighting outlet(s) are installed
for interior stairways, there shall be a wall switch at each
floor level, and landing level that includes an entryway, to
control the lighting outlet(s) where the stairway between
floor levels has six risers or more.

Exception to (A)(2)(a), (A)(2)(b), and (A)(2)(c): In
hallways, in stairways, and at outdoor entrances, remote,
central, or automatic control of lighting shall be
permitted.

(3) Storage or Equipment Spaces. For attics, underiloor
spaces, utility rooms, and basements, at least one lighting
outlet containing a switch or controlled by a wall switch
shall be installed where these spaces are used for storage
or contain equipment requiring servicing. At least one
point of control shall be at the usual point of entry to
these spaces. The lighting outlet shall be provided at or
near the equipment requiring servicing.

(B) Guest Rooms or Guest Suites. In hotels, motels, or
similar occupancies, guest rooms or guest suites shall
have at least one wall switch-controlled lighting outlet
installed in every habitable room and bathroom.

Exception No. 1: In other than bathrooms and kitchens
where provided, one or more receptacles controlled by a
wall switch shall be permitted in lieu of lighting outlets.

Exception No. 2: Lighting outlets shall be permitted to be
controlled by occupancy sensors that are (I) in addition
to wall switches or (2) located at a customary wall switch
location and equipped with a manual override that allows
the sensor to function as a wall switch.

(C) Other Than Dwelling Units. For attics and underiloor
spaces containing equipment requiring servicing, such as
heating, air-conditioning, and refrigeration equipment, at
least one lighting outlet containing a switch or controlled
by a wall switch shall be installed in such spaces. At least
one point of control shall be at the usual point of entry to
these spaces. The lighting outlet shall be provided at or
near the equipment requiring servicing. /

ARTICLE 215

215.1 Scope. This article covers the installation

requirements, overcurrent protection requirements,
minimum size, and ampacity of conductors for feeders
supplying branch-circuit loads.

Exception: Feeders for electrolytic cells as covered in
668.3(C)(1) and (C)(4).

2010 California Electrical Code

70-55

215.2

ARTICLE 215 - FEEDERS

215.2 Minimum Rating and Size.

(A) Feeders Not More Tlian 600 Volts.

(1) General. Feeder conductors shall have an ampacity
not less than required to supply the load as calculated in
Parts III, IV, and V of Article 220. The minimum feeder-
circuit conductor size, before the application of any
adjustment or correction factors, shall have an allowable
ampacity not less than the noncontinuous load plus 125
percent of the continuous load.

Exception No. 1: Where the assembly, including the
overcurrent devices protecting the feeder(s), is listed for
operation at 100 percent of its rating, the allowable
ampacity of the feeder conductors shall be permitted to be
not less than the sum of the continuous load plus the
noncontinuous load.
Exception No. 2: ^r^im^S^mS^

The size of the feeder circuit grounded conductor shall
not be smaller than that required by 250.122, except that
250.122(F) shall not apply where grounded conductors are
run in parallel.

Additional minimum sizes shall be as specified in
215.2(A)(2) and (A)(3) under the conditions stipulated.

(2) Ampacity Relative to Service Conductors. The
feeder conductor ampacity shall not be less than that of the
service conductors where the feeder conductors carry the
total load supplied by service conductors with an ampacity
of 55 amperes or less.

(3) Individual Dwelling Unit or Mobile Home Conductors.
Feeder conductors for individual dwelling units or mobile
homes need not be larger than service conductors.
Paragraph 310.15(B)(6) shall be permitted to be used for
conductor size.

FPN No. 1 : See Examples Dl through Dl 1 in Annex D.
FPN No. 2: Condiictors for feeders as defined in Article
100, sized to prevent a voltage drop exceeding 3 percent at
the farthest outlet of power, heating, and lighting loads, or
combinations of such loads, and where the maximum total
voltage drop on both feeders and branch circuits to the
farthest outlet does not exceed 5 percent, will provide
reasonable efficiency of operation.

(B) Feeders over 600 Volts. The ampacity of conductors
shall be in accordance with 310.15 and 310.60 as
applicable. Where installed, the size of the feeder-circuit
grounded conductor shall not be smaller than that required
by 250.122, except that 250.122(F) shall not apply where
grounded conductors are run in parallel. Feeder conductors
over 600 vohs shall be sized in accordance with
215.2(B)(1), (B)(2), or (B)(3).

(1) Feeders Supplying Transformers. The ampacity of
feeder conductors shall not be less than the sum of the
nameplate ratings of the transformers supplied when only
transformers are supplied.

(2) Feeders Supplying Transformers and Utilization
Equipment. The ampacity of feeders supplying a
combination of transformers and utilization equipment
shall not be less than the sum of the nameplate ratings of
the transformers and 125 percent of the designed potential
load of the utilization equipment that will be operated
simultaneously.

(3) Supervised Installations. For supervised installations,
feeder conductor sizing shall be permitted to be determined
by qualified persons under engineering supervision.
Supervised installations are defined as those portions of a
facility where all of the following conditions are met:

(1) Conditions of design and installation are provided under
engineering supervision.

(2) Qualified persons with documented training and experience

in over 600-volt systems provide maintenance,
monitoring, and servicing of the system.

215.3 Overcurrent Protection. Feeders shall be protected
against overcurrent in accordance with the provisions of
Part I of Article 240. Where a feeder supplies continuous
loads or any combination of continuous and noncontinuous
loads, the rating of the overcurrent device shall not be less
than the noncontinuous load plus 125 percent of the
continuous load.

Exception No. 1: Where the assembly, including the
overcurrent devices protecting the feeder(s), is listed for
operation at 100 percent of its rating, the ampere rating of
the overcurrent device shall be permitted to be not less than
the sum of the continuous load plus the noncontinuous load.
Exception No. 2: Overcurrent protection for feeders over
600 volts, nominal, shall comply with Part XI of Article 240.

215.4 Feeders with Common Neutral p^Siliol.

(A) Feeders with Common Neutral. HfejJ^ three sets of 3-
wire feeders or two sets of 4-wire or 5 -wire feeders shall be
permitted to utilize a common neutral.

(B) In Metal Raceway or Enclosure. Where installed in a
metal raceway or other metal enclosure, all conductors of
all feeders using a common neutral |afl[49it<g shall be
enclosed within the same raceway or other enclosure as
required in 300.20.

215.5 Diagrams of Feeders. If required by the authority
having jurisdiction, a diagram showing feeder details shall
be provided prior to the installation of the feeders. Such a
diagram shall show the area in square feet of the building or
other structure supplied by each feeder, the total calculated
load before applying demand factors, the demand factors
used, the calculated load after applying demand factors, and
the size and type of conductors to be used.

215.6 Feeder gg^^^g Grounding W^^^^^. Where a
feeder supplies branch circuits in which equipment
grounding conductors are required, the feeder shall include
or provide |]^^u|^^ grounding 'c^^SctjS in accordance
with the provisions of 250.134, to which the equipment
grounding conductors of the branch circuits shall be

70-56

2010 California Electrical Code

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

220.3

connected Wt^re fe feeder $uppHes a separate bui}&
stocture;,:tih;e re^mtemefib p|^250,32^^ sM apjlyj

215.7 Ungrounded Conductors Tapped from Grounded
Systems. Two-wire dc circuits and ac circuits of two or more
ungrounded conductors shall be permitted to be tapped from
the ungrounded conductors of circuits having a grounded
neutral conductor. Switching devices in each tapped circuit
shall have a pole in each ungrounded conductor.

215.9 Ground-Fault Circuit-Interrupter Protection for
Personnel. Feeders supplying 15- and 20-ampere receptacle
branch circuits shall be permitted to be protected by a
ground-fault circuit interrupter in lieu of the provisions for
such interrupters as specified in 210.8 and 590.6(A).

215.10 Ground-Fault Protection of Equipment. Each
feeder disconnect rated 1000 amperes or more and installed
on solidly grounded wye electrical systems of more than
150 vohs to ground, but not exceeding 600 volts phase-to-
phase, shall be provided with ground-fault protection of
equipment in accordance with the provisions of 230.95.

FPN: For buildings that contain health care occupancies, see
the requirements of 5 1 7 . 1 7 .

Exception No. 1: The provisions of this section shall not
apply to a disconnecting means for a continuous industrial
process where a nonorderly shutdown will introduce
additional or increased hazards.

215.12 Identificatipn for Feeders.

(A) Grounded Conductor. The grounded conductor of a
feeder shall be identified in accordance with 200.6.

(B) Equipment Grounding Conductor. The equipment
grounding conductor shall be identified in accordance with
250,119.

(C) Ungrounded Conductors. Where the premises wiring
system has feeders supplied from more than one nominal
voltage system, each ungrounded conductor of a feeder
shall be identified by jphase , pr Jm^^^^

[termination, conilection^ aSd splice points, The means of
identification shall be permitted to be by separate color
coding, marking tape, tagging, or other approved means.
JrheJ~^ethod;utUiz^^ origmating wit§B each

peder panelboard or sirmJar feeder dtstFibutionequipmenf
khajj feidoctoenteid in a maimer ftiat is readily available or
shall be permanently posted at each feeder panelboard or
similar feeder distribution equipment.

Braii€K-€irciiit9 Feeder^ and Service

Exception No. 2: The provisions of this section shall Mot
apply if ground fault protection of equipment is provided
on the supply side of the feeder hnS on iHeload side of dm
tramfqhr^^r su^ the feeder^-.

215.11 Circuits Derived from Autotransformers.

Feeders shall not be derived from autotransformers unless
the system supplied has a grounded conductor that is
electrically connected to a grounded conductor of the
system supplying the autotransformer.

Exception No. J: An autotransformer shall be permitted
without the connection to a grounded conductor where
transforming from a nominal 208 volts to a nominal 240-
volt supply or similarly from 240 volts to 208 volts.

Exception No. 2: In industrial occupancies, where conditions of
maintenance and supervision ensure that only qualified persons
service the installation, autotransformers shall be permitted to
supply nominal 600-volt loads fi-om nominal 480-volt systems,
and 480-volt loads from nominal 600-volt systems, without the
connection to a similar grounded conductor

I. General

220.1 Scope. This article provides requirements for
calculating branch-circuit, feeder, and service loads. Part I
provides for general requirements for calculation methods.
Part II provides calculation methods for branch-circuit loads.
Parts III and IV provide calculation methods for feeders and
services. Part V provides calculation methods for farms.

FPN: See Figure 220. 1 for information on the organization
of Article 220.

220.3 Application of Otiier Articles. In other articles
applying to the calculation of loads in specialized
applications, there are requirements provided in Table
220.3 that are in addition to, or modifications of, those
within this article.

2010 California Electrical Code

70-57

220.5

ARTICLE 220 -BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

fart I General

Part li Branch-circuit load calculations

Part Hi
Feeder and
service load
calculations

220.61

Neutral
Loads

Part IV

Optional

feeder and

service load

calculations

Farm dwellings
only

Farm dwellings

only

Part V Farm load calculations

Figure 220.1 Branch-Circuit, Feeder, and Service

Calculation Methods.
220.5 Calculations.

(A) Voltages. Unless other voltages are specified, for purposes
of calculating branch-circuit and feeder loads, nominal system
voltages of 120, 120/240, 208Y/120, 240, 347, 480Y/277, 480,
600Y/347, and 600 volts shall be used.

(B) Fractions of an Ampere. Where calculations result in a
fraction of an ampere that is less than 0.5, such fractions shall
be permitted to be dropped.

n. Branch-Circuit Load Calculations

220.10 General. Branch-circuit loads shall be calculated as

shown in 220.12, 220.14, and 220.16.

220.12 Lighting Load for Specified Occupancies. A unit

load of not less than that specified in Table 220.12 for

occupancies specified therein shall constitute the minimum

lighting load, area involved. For dweUing units, the calculated

floor area shall not include open porches, garages, or unused

or unfinished spaces not adaptable for future use.

•

Table 220.3 Additional Load Calculation References

Calculation

Article

Section (or Part)

Air-Conditioning and Refrigerating Equipment, Branch-Circuit

440

PartrV

Conductor Sizing

Cranes and Hoists, Rating and Size of Conductors

610

610.14

Electric Welders, ampacity calculations

630

630.11,630.31

Electrically Driven or Controlled Irrigation Machines

675

675.7(A), 675.22(A)

Elk^filledimpkpSrkiiig '$pac|

l?|

Electrolytic Cell Lines

668

668.3(C)

Electroplating, Branch-Circuit Conductor Sizing

669

669.5

Elevator Feeder Demand Factors

620

620.14

Fire Pumps, Voltage Drop (mandatory calculation)

695

695.7

Fixed Electric Heating Equipment for Pipelines and Vessels, Branch-

427

427.4

Circuit Sizing

Fixed Electric Space Heating Equipment, Branch-Circuit Sizing

424

424.3

Fixed Outdoor Electric Deicing and Snow-Mehing Equipment,

426

426.4

Branch-Circuit Sizing

Industrial Machinery, Supply Conductor Sizing

670

670.4(A)

Marinas and Boatyards, Feeder and Service Load Calculations

555

555.12

Mobile Homes, Manufactured Homes, and Mobile Home Parks, Total

550

550.18(B)

Load for Determining Power Supply

Mobile Homes, Manufactured Homes, and Mobile Home Parks,

550

550.31

Allowable Demand Factors for Park Electrical Wiring Systems

Motion Picture and Television Studios and Similar Locations - Sizing

530

530.19

of Feeder Conductors for Television Studio Sets

Motors, Feeder Demand Factor

430

430.26

Motors, Multimotor and Combination-Load Equipment

430

430.25

Motors, Several Motors or a Motor(s) and Other Load(s)

430

430.24

Over 600 Volt Branch Circuit Calculations

210

210.19(B)

Over 600 Volt Feeder Calculations

215

215.2(B)

Phase Converters, Conductors

455

455.6

Recreational Vehicle Parks, Basis of Calculations

551

551.73(A)

Sensitive Electrical Equipment, Voltage Drop (mandatory calculation)

647

647.4(D)

Solar Photovoltaic Systems, Circuit Sizing and Current

690

690.8

Storage-Type Water Heaters

422

422.11(E)

Theaters, Stage Switchboard Feeders

520

520.27

70-58

2010 California Electrical Code

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

220.14

FPN: The unit values herein are based on minimum load
conditions and 100 percent power factor and may not
provide sufficient capacity for the installation contemplated.

Table 220.12 General Lighting Loads by Occupancy

Unit Load

Volt-Amperes

per Square

Type of Occupancy

Meter

Foot

Armories and auditoriums

Banks

39b

^Vih

Barber shops and beauty

parlors

Churches

Clubs

Court rooms

Dvi^elling unitsa

Garages — commercial

(storage)

Hospitals

Hotels and motels, including

apartment houses without

provision for cooking by

tenants^

Industrial commercial (loft)

buildings

Lodge rooms

\V2

Office buildings

39b

3V^

Restaurants

Schools

Stores

Warehouses (storage)

In any of the preceding

occupancies except one-

family dwellings and

individual dwelling units

of two-family and

muhifamily dwellings:

Assembly halls and

auditoriums

Halls, corridors, closets,

stairways

Storage spaces

aSee220.14(J).
bSee220.14(K).

Exception: The loads of outlets serving switchboards and
switching frames in telephone exchanges shall be waived
from the calculations.

(A) Specific Appliances or Loads. An outlet for a specific
appliance or other load not covered in 220.14(B) through
(L) shall be calculated based on the ampere rating of the
appliance or load served.

(B) Electric Dryers and Household Electric Cooking
Appliances. Load calculations shall be permitted as
specified in 220.54 for electric dryers and in 220.55 for
electric ranges and other cooking appliances.

(C) Motor Loads. Outlets for motor loads shall be
calculated in accordance with the requirements in 430,22,
430.24, and 440.6.

(D) Luminaires. An outlet supplying luminaire(s) shall be
calculated based on the maximum volt-ampere rating of the
equipment and lamps for vv^hich the luminaire(s) is rated.

(E) Heavy-Duty Lampholders. Outlets for heavy-duty
lampholders shall be calculated at a minimum of 600 volt-
amperes.

(F) Sign and Outline Lighting. Sign and outline lighting
outlets shall be calculated at a minimum of 1200 volt-
amperes for each required branch circuit specified in
600.5(A).

(G) Show Windows. Shov^ windows shall be calculated in
accordance with either of the following:

(1) The unit load per outlet as required in other provisions

of this section

(2) At 200 volt-amperes per 300 mm (1 ft) of show window

(H) Fixed Multioutlet Assemblies. Fixed multioutlet
assemblies used in other than dwelling units or the guest
rooms or guest suites of hotels or motels shall be calculated
in accordance with (H)(1) or (H)(2). For the purposes of
this section, the calculation shall be permitted to be based
on the portion that contains receptacle outlets.

(1) Where apphances are unlikely to be used simultaneously,

each 1.5 m (5 ft) or fi-action thereof of each separate and
continuous length shall be considered as one outlet of not
less than 180 volt-amperes.

(2) Where apphances are likely to be used simultaneously, each

300 mm (1 ft) or fraction thereof shall be considered as an
outlet of not less than 180 volt-amperes.

(I) Receptacle Outlets. Except as covered in 220.14(J) and
(K), receptacle outlets shall be calculated at not less than
180 volt-amperes for each single or for each multiple
receptacle on one yoke. A single piece of equipment
consisting of a multiple receptacle comprised of four or
more receptacles shall be calculated at not less than 90
volt-amperes per receptacle. This provision shall not be
applicable to the receptacle outlets specified in
210.11(C)(1) and (C)(2).

(J) Dwelling Occupancies. In one-family, two-family, and
multifamily dwellings and in guest rooms or guest suites of
hotels and motels, the outlets specified in (J)(l), (J)(2), and
(J)(3) are included in the general hghting load calculations
of 220.12. No additional load calculations shall be required
for such outlets.

2010 California Electrical Code

70-59

220.16

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

(1) All general-use receptacle outlets of 20-ampere rating
or less, including receptacles connected to the circuits

in 210.11(C)(3)

(2) The receptacle outlets specified in 210.52(E) and (G)

(3) The lighting outlets specified in 210.70(A) and (B)

(K) Banks and Office Buildings. In banks or office
buildings, the receptacle loads shall be calculated to be the
largerof(l)or(2):

(1) The calculate load from 220. 14(1)

(2) 1 1 volt-amperes/m2 or 1 volt-ampere/ft2

(L) Other Outlets. Other outlets not covered in 220.14(A)

through (K) shall be calculated based on 1 80 volt-amperes
per outlet.

220.16 Loads for Additions to Existing Installations.

(A) Dwelling Units. Loads added to an existing dwelling
unit(s) shall comply with the following as applicable:

(1) Loads for structural additions to an existing dwelling
unit or for a previously un wired portion of an existing
dwelling unit, either of which exceeds 46.5 m2 (500
ft2), shall be calculated in accordance with 220.12 and
220.14.

(2) Loads for new circuits or extended circuits in
previously wired dwelling units shall be calculated in
accordance with either 220.12 or 220.14, as applicable.

(B) Other Than Dwelling Units. Loads for new circuits or

extended circuits in other than dwelling units shall be
calculated in accordance with either 220.12 or 220.14, as
applicable.

220.18 Maximum Loads. The total load shall not exceed
the rating of the branch circuit, and it shall not exceed the
maximum loads specified in 220.18(A) through (C) under
the conditions specified therein.

(A) Motor-Operated and Combination Loads. Where a

circuit supplies only motor-operated loads, Article 430
shall apply. Where a circuit supphes only air-conditioning
equipment, refrigerating equipment, or both, Article 440
shall apply. For circuits supplying loads consisting of
motor-operated utilization equipment that is fastened in
place and has a motor larger than 1/8 hp in combination
with other loads, the total calculated load shall be based on
125 percent of the largest motor load plus the sum of the
other loads.

(B) Inductive Lighting Loads. For circuits supplying
Hghting units that have ballasts, transformers, or
autotransformers, the calculated load shall be based on the
total ampere ratings of such units and not on the total watts
of the lamps.

(C) Range Loads. It shall be permissible to apply demand
factors for range loads in accordance with Table 220.55,
including Note 4.

III. Feeder and Service Load Calculations

220.40 General. The calculated load of a feeder or service
shall not be less than the sum of the loads on the branch
circuits supplied, as determined by Part II of this article,
after any applicable demand factors permitted by Part III or
IV or required by Part V have been appHed.

FPN: See Examples Dl(a) through DIG in Annex D. See
220.18(B) for the maximum load in amperes permitted for
lighting units operating at less than 100 percent power
factor.

220.42 General Lighting. The demand factors specified in
Table 220.42 shall apply to that portion of the total branch-
circuit load calculated for general illumination. They shall
not be applied in determining the number of branch circuits
for general illumination.

220.43 Show-window and Track Lighting.

(A) Show Windows. For show-window lighting, a load of
not less than 660 volt-amperes/linear meter or 200 volt-
amperes/linear foot shall be included for a show window,
measured horizontally along its base.

FPN: See 220.14(G) for branch circuits supplying show
windows.

(B) Track Lighting. For track hghting in other than
dwelling units or guest rooms or guest suites of hotels or
motels, an additional load of 150 voh-amperes shall be
included for every 600 mm (2 ft) of lighting track or
fraction thereof Where multicircuit track is installed, the
load shall be considered to be divided equally between the
track circuits.

220.44 Receptacle Loads — Other Than Dwelling Units.

Receptacle loads calculated in accordance with 220.14(H)
and (I) shall be permitted to be made subject to the demand
factors given in Table 220.42 or Table 220.44.

70-60

2010 California Electrical Code

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

220.55

Table 220.42 Lighting Load Demand Factors

Portion of Lighting

Load to Which

Demand Factor

Type of Occupancy

Applies
(Volt-Amperes)

(%)

Dwelling units

First 3000 or less at

100

From 3001 to

120,000 at

Remainder over

120,000 at

Hospitals*

First 50,000 or less at

Remainder over

50,000 at

Hotels and motels,

First 20,000 or less at

including

From 20,001 to

apartment houses

100,000 at

without provision

Remainder over

for cooking by

100,000 at

tenants*

Warehouses

First 12,500 or less at

100

(storage)

Remainder over
12,500 at

All others

Total volt-amperes

100

The demand factors of this table shall not apply to the calculated
load of feeders or services supplying areas in hospitals, hotels,
and motels where the entire lighting is likely to be used at one
time, as in operating rooms, ballrooms, or dining rooms. [OSHPD
1] The factors of Table 220.42 shall not be applied in the
following areas: surgery suite, including recovery; emergency
department, kitchen, food service, dining, critical care areas as
defined in Article 517, elevator lobbies, corridors, inpatient nurse
stations, and loads connected to the life safety branch or the
critical branch of the emergency system. Administrative areas
shall be included in "All others " Type of Occupancy.

Table 220.44 Demand Factors for Non-Dwelling Receptacle
Loads

Portion of Receptacle Load to
Which Demand Factor Applies
(Volt-Amperes)

Demand Factor W^

First 10 kVA or less at
Remainder over 10 kVA at

100

220.50 Motors. Motor loads shall be calculated in
accordance with 430.24, 430.25, and 430.26 and v^ith 440.6
for hermetic refrigerant motor compressors.

220.51 Fixed Electric Space Heating. Fixed electric
space-heating loads shall be calculated at 100 percent of
the total connected load. However, in no case shall a feeder
or service load current rating be less than the rating of the
largest branch circuit supplied.

Exception: Where reduced loading of the conductors
results from units operating on duty-cycle, intermittently,
or from all units not operating at the same time, the
authority having jurisdiction may grant permission for
feeder and service conductors to have an ampacity less

than 100 percent, provided the conductors have an
ampacity for the load so determined.

220.52 Small-Appliance and Laundry Loads —
Dwelling Unit.

(A) Small-Appliance Circuit Load. In each dwelling unit,
the load shall be calculated at 1500 volt-amperes for each
2-wire small-appliance branch circuit las ,^C0Yere<| by
2 10. 11 (C)(1). Where the load is subdivided through two or
more feeders, the calculated load for each shall include not
less than 1500 volt-amperes for each 2-wire small-
appliance branch circuit. These loads shall be permitted to
be included with the general lighting load and subjected to
the demand factors provided in Table 220.42.
Exception: The individual branch circuit permitted by
210.52(B)(1), Exception No. 2, shall be permitted to be
excluded from the calculation required by 220. 52.

(B) Laundry Circuit Load. A load of not less than 1500
volt-amperes shall be included for each 2-wire laundry
branch circuit installed as covered by 210.11(C)(2). This
load shall be permitted to be included with the general
lighting load and subjected to the demand factors provided
in Table 220.42.

220.53 Appliance Load — Dwelling Unit(s).

It shall be permissible to apply a demand factor of 75
percent to the nameplate rating load of four or more
appliances fastened in place, other than electric ranges,
clothes dryers, space-heating equipment, or air-
conditioning equipment, that are served by the same feeder
or service in a one-family, two-family, or multifamily
dwelling.

220.54 Electric Clothes Dryers — Dwelling Unit(s).
The load for household electric clothes dryers in a dwelling
unit(s) shall be either 5000 watts (volt-amperes) or the
nameplate rating, whichever is larger, for each dryer
served. The use of the demand factors in Table 220.54 shall
be permitted. Where two or more single-phase dryers are
supplied by a 3 -phase, 4- wire feeder or service, the total
load shall be calculated on the basis of twice the maximum
number connected between any two phases. Kiloyglt^^
'amperes (kV A) shall be coBsidered equivalent to kilowatts!
ji^W) for loads caiculated in this section;

220.55 Electric Ranges and Other Cooking Appliances —
Dwelling Unit(s). The load for household electric ranges,
wall-mounted ovens, counter-mounted cooking units, and
other household cooking appliances individually rated in
excess of VA kW shall be permitted to be calculated in
accordance with Table 220.55. Kilo volt-amperes (kVA)
shall be considered equivalent to kilowatts (kW) for loads
calculated under this section.

2010 California Electrical Code

70-61

220.56

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

Table 220.54 Demand Factors for Household Electric Clothes
Dryers

Number of Demand Factor

Dryers (%)

1^ . 100

5 85

6 75

7 65

8 60

9 55

10 50

11 47

- "'- -' t2-23; ' '' '4^Al^S¥/i§t'ikh^'^^iik&eii^^ 11]

24-42 immtM'&A iotm(ii^m:^tm^u0i

43 and over 25%.

Where two or more single-phase ranges are supplied
by a 3 -phase, 4-wire feeder or service, the total load shall
be calculated on the basis of tw^ice the maximum number
connected between any two phases.

FPN No. 1 : See Example D5(A) in Annex D.

FPN No. 2: See Table 220.56 for commercial cooking
equipment.

FPN No. 3: See the examples in Annex D.

220.56 Kitchen Equipment — Other Than Dwelling
Unit(s).

It shall be permissible to calculate the load for commercial
electric cooking equipment, dishwasher booster heaters,
water heaters, and other kitchen equipment in accordance
with Table 220.56. These demand factors shall be applied
to all equipment that has either thermostatic control or
intermittent use as kitchen equipment. These demand
factors shall not apply to space-heating, ventilating, or air-
conditioning equipment.

However, in no case shall the feeder or service
calculated load be less than the sum of the largest two
kitchen equipment loads.

Table 220.56 Demand Factors for Kitchen Equipment — Other
Than Dwelling Unit(s)

Number of Units of

Demand Factor

Equipment

■

100

6 and over

220.60 Noncoincident Loads. Where it is unlikely that
two or more noncoincident loads will be in use
simultaneously, it shall be permissible to use only the
largest load(s) that will be used at one time for calculating
the total load of a feeder or service.

220.61 Feeder or Service Neutral Load.

(A) Basic Calculation. The feeder or service neutral load
shall be the maximum unbalance of the load determined by
this article. The maximum unbalanced load shall be the
maximum net calculated load between the neutral
i<>litt?Mi ^^^ ^^y ^^^ ungrounded conductor.
Exception: For 3 -wire, 2-phase or 5 -wire, 2 -phase
systems, the maximum unbalanced load shall be the
maximum net calculated load between the neutral
pmdujdtgfjm^^ any one ungrounded conductor multiplied
by 140 percent.

(B) Permitted Reductions. A service or feeder supplying
the following loads shall be permitted to have an additional
demand factor of 70 percent applied to the amount in
220.61(B)(1) or portion of the amount in 220.61(B)(2)
determined by the basic calculation:

(1) A feeder or service supplying household electric ranges,
wall-mounted oyens, counter-mounted cooking units,
and electric dryers, where the maximum unbalanced
load has been determined in accordance with Table
220.55 for ranges and Table 220.54 for dryers

(2) That portion of the unbalanced load in excess of 200
amperes where the feeder or service is supplied from a
3 -wire dc or single-phase ac system; or a 4-wire, 3-
phase, 3-wire, 2-phase system; or a 5-wire, 2-phase
system

(C) Prohibited Reductions. There shall be no reduction of
the neutral or grounded conductor capacity applied to the
amount in 220.61(C)(1), or portion of the amount in (C)(2),
from that determined by the basic calculation:

(1) Any portion of a 3-wire circuit consisting of 2 tMgr||tt]^^
|gSdi|?fe^g and the neutral jcjoStc^ of a 4-wire, 3-phase,
wye-connected system

(2) That portion consisting of nonlinear loads supplied from a
4-wire, v^e-connected, 3-phase system

FPN No. 1 : See Examples Dl(a), Dl(b), D2(b), D4(a), and D5(a)
in Annex D.

FPN No. 2: A 3-phase, 4-wire, wye-connected power
system used to supply power to nonlinear loads may
necessitate that the power system design allow for the

possibility of high harmonic neutral-^j

currents.

IV. Optional Feeder and Service Load Calculations
220.80 General. Optional feeder and service load
calculations shall be permitted in accordance with Part IV.

70-62

2010 California Electrical Code

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 220.80

Table 220.55 Demand Factors and Loads for Household Electric Ranges, Wall-Mounted Ovens, Counter-Mounted Cooking Units, and
Other Household Cooking Appliances over P/i kW Rating (Column C to be used in all cases except as otherwise permitted in Note 3.)

Demand Factor (%) (See Notes)

Column C
Column A Column B Maximum Demand (kW)

Number of Appliances (Less than 3^2 kW Rating) (3!/2 kW |fi5iipi'^j3 kW Rating) (See Notes) (Not over 12 kW Rating)

1 80 80 8

2 75 65 • 11

3 70 55 14

4 66 50 17

5 62 45 20

6 59 43 21

7 56 40 22

8 53 36 23

9 51 35 24

10 49 34 - 25

11 .47 32 26

12 45 32 27

13 43 32 28

14 41 32 29

15 _40 32 30

16 39 28 31

17 38 28 32

18 37 28 33

19 36 28 34

20 35 28 35

21 34 26 36

22 33 26 37

23 32 26 38

24 31 26 39

25 30 26 40

26-30 30 24 1 5 kW + 1 kW for each range

31-40 30 22

41-50 30 20 25 kW + y4 kW for each range

51-60 .30 18

61 and over 30 16

Notes:

1. Over 12 kW through 27 kW ranges all of same rating. For ranges individually rated more than 12 kW but not more than 27 kW, the
maximum demand in Column C shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the
rating of individual ranges exceeds 12 kW.

2. Over 8% kW through 27 kW ranges of unequal ratings. For ranges individually rated more than %Ya kW and of different ratings, but none
exceeding 27 kW, an average value of rating shall be calculated by adding together the ratings of all ranges to obtain the total connected
load (using 12 kW for any range rated less than 12 kW) and dividing by the total number of ranges. Then the maximum demand in Column
C shall be increased 5 percent for each kilowatt or major fraction thereof by which this average value exceeds 12 kW.

3. Over VA kW through ^V^ kW. In Heu of the method provided in Column C, it shall be permissible to add the nameplate ratings of all
household cooking appliances rated more than W^ kW but not more than %Va kW and multiply the sum by the demand factors specified in
Column A or Column B for the given number of appliances. Where the rating of cooking appliances falls under both Column A and
Column B, the demand factors for each column shall be applied to the appliances for that column, and the results added together.

4. Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The
branch-circuit load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The
branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch
circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appHances and treating this total
as equivalent to one range.

5. This table shall also apply to household cooking appliances rated over VA kW and used in instructional programs.

20 1 California Electrical Code 70—63

220.82

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

220.82 Dwelling Unit.

(A) Feeder and Service Load. This section applies to a
dwelling unit having the total connected load served by a
single 120/240-volt or 208Y/120-voh set of 3-wire service
or feeder conductors with an ampacity of 100 or greater. It
shall be permissible to calculate the feeder and service
loads in accordance with this section instead of the method
specified in Part III of this article. The calculated load shall
be the resuk of adding the loads from 220.82(B) and (C).
Feeder and service-entrance conductors whose calculated
load is determined by this optional calculation shall be
permitted to have the neutral load determined by 220.6 1 .

(B) General Loads. The general calculated load shall be
not less than 100 percent of the first 10 kVA plus 40
percent of the remainder of the following loads:

(1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general
lighting and general-use receptacles. The floor area for
each floor shall be calculated from the outside
dimensions of the dwelling unit. The calculated floor
area shall not include open porches, garages, or unused
or unfinished spaces not adaptable for fiiture use.

(2) 1500 volt-amperes for each 2-wire, 20-ampere small-
appliance branch circuit and each laundry branch
circuit covered j&21(hii(CIl^

(3) The nameplate rating of the foiiowing:

iJ All apphances that are fastened in place, permanently
connected, or located to be on a specific circuit

J Ranges, wall-mounted ovens, counter-mounted cooking
units

jl Clothes dryers Siat am ti^ftconnect^^
branch circuii specified m item (2)

4^ Water heaters

(4) The nameplate ampere or kVA rating of all permanently
connected motors not included in item (3).

(1) 100 percent of the nameplate rating(s) of the air
conditioning and cooling.

(2) 100 percent of the nameplate rating(s) of the h^^t:gumfi
when the heat pump is used without any supplemental
electric heating.

(3) 100 percent of the nameplate rating(s) of the heat pump
compressor and 65 percent of the supplemental electric
heating for central electric space-heating systems. If
the heat pump compressor is prevented from operating
at the same time as the supplementary heat, it does not
need to be added to the supplementary heat for the
total central space heating load.

(4) 65 percent of the nameplate rating(s) of electric space
heating if less than four separately controlled units.

(5) 40 percent of the nameplate rating(s) of electric space
heating if four or more separately controlled units.

(6) 100 percent of the nameplate ratings of electric thermal
storage and other heating systems where the usual load
is expected to be continuous at the frill nameplate
value. Systems qualifying under this selection shall not
be calculated under any other selection in 220.82(C).

220.83 Existing Dwelling Unit. This section shall be
permitted to be used to determine if the existing service or
feeder is of sufficient capacity to serve additional loads.
Where the dwelling unit is served by a 120/240-volt or
208Y/120-volt, 3-wire service, it shall be permissible to
calculate the total load in accordance with 220.83(A) or (B).

(A) Where Additional Air-Conditioning Equipment or
Electric Space-Heating Equipment Is Not to Be
Installed. The following formula shall be used for existing
and additional new loads.

Load (kVA)

Percent of Load

First 8 kVA of load at
Remainder of load at

100
40

Load calculations shall include the following:

(1) General lighting and general-use receptacles at 33 volt-
amperes/m2 or 3 volt-ampere s/ft2 as determined by

220.12

(2) 1500 volt-amperes for each 2-wire, 20-ampere small-
appliance branch circuit and each laundry branch
circuit goyer^K2l£il|Q

(3) ithi^mmepUt€ i^^

aj; All appliances that ai*© fastened in place,' permanently
Iccraiected, or located fe> fee cm a specific circuit

J>;^Rmiges^ waJtmouM

f:i jCfoth*^ ^er$ liikt tfe not; comiected ; to the^^ M
bitocii cjrcmtspeyfi^ m

(i Water teatSrs

(B) Where Additional Air-Conditioning Equipment or
Electric Space-Heating Equipment Is to Be Installed.

The following formula shall be used for existing and
additional new loads. The larger connected load of air-
conditioning or space-heating, but not both, shall be used.

Load

Percent of Load

Air-conditioning equipment

100

Central electric space heating

100

Less than four separately controlled

100

space-heating units

First 8 kVA of all other loads

100

Remainder of all other loads

70-64

2010 California Electrical Code

ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

220.86

Other loads shall include the following:

(1) General lighting and general-use receptacles at 33 volt-
amperes/m2 or 3 volt-amperes/ft2 as determined by
220.12

(2) 1500 volt-amperes for each 2-wire, 20-ampere small-
appliance branch circuit and each laundry branch
circuit coygt^ iii 2 10, ll(C^I)?B03^ (JS)(^

(3) TheVna£eplpirafi%rf

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220.84 Multifamily Dwelling.

(A) Feeder or Service Load. It shall be permissible to
calculate the load of a feeder or service that supplies three
or more dwelling units of a multifamily dwelling in
accordance with Table 220.84 instead of Part III of this
article if all the following conditions are met:

(1) No dwelling unit is suppUed by more than one feeder.

(2) Each dwelling unit is equipped with electric cooking
equipment.

Exception: When the calculated load for multifamily
dwellings without electric cooking in Part III of this article
exceeds that calculated under Part IV for the identical load
plus electric cooking (based on 8 kWper unit), the lesser of
the two loads shall be permitted to be used.

(3) Each dwelling unit is equipped with either electric
space heating or air conditioning, or both. Feeders and
service conductors whose calculated load is
determined by this optional calculation shall be
permitted to have the neutral load determined by
220.61.

(B) House Loads. House loads shall be calculated in
accordance with Part III of this article and shall be in
addition to the dwelling unit loads calculated in accordance
with Table 220.84.

(1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general
lighting and general-use receptacles

(2) 1500 volt-amperes for each 2-wire, 20-ampere small-
appliance branch circujt and each laundry branch

circuit )^^\xxmMMxyMM)&i

(3) The nameplate rating oi\%^:t(Mo^^m^^^

a: All appliances that are fastened in place, permanently
connected, or located to be on a specific circuit

Table 220.84 Optional

Calculations

— Demand Factors for

Three or More Multifamily Dwelling

Units

Number of

Demand Factor

Dwelling Units

i%)

3-5

6-7

8-10

12-13
14-15
16-17
18-20

42
41
40
39
38

22-23
24-25
26-27
28-30

37
36
35
34
33

31
32-33
34-36
37-38
39^2

32
31
30
29
28

43^5
46-50
51-55
56-61
62 and over

27
26

25
24
23

y Ranges, wall-mounted ovens, counter-mounted cooldng

units
y Clothes ^[ryersjbat aire npt cpimecfed to j&e Jautidry

Ij Water heaters
(4) The nameplate ampere or kVi§ rating of all
t^emanentlyc^ motors not included in item (3)

(5) Thejarger of the air-conditioning load or the Hied
gleetn3 space-heating load

220.85 Two Dwelling Units. Where two dwelling units
are supplied by a single feeder and the calculated load
under Part III of this article exceeds that for three identical
units calculated under 220.84, the lesser of the two loads
shall be permitted to be used.

220.86 Schools. The calculation of a feeder or service
load for schools shall be permitted in accordance with
Table 220.86 in lieu of Part III of this article where
equipped with electric space heating, air conditioning, or
both. The connected load to which the demand factors of
Table 220.86 apply shall include all of the interior and
exterior lighting, power, water heating, cooking, other
loads, and the larger of the air-conditioning load or spcice-
heating load within the building or structure.

2010 California Electrical Code

70-65

220.87

ARTICLE 220 -BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS

Feeders and service conductors whose calculated load
is determined by this optional calculation shall be permitted
to have the neutral load determined by 220.61. Where the
building or structure load is calculated by this optional
method, feeders within the building or structure shall have
ampacity as permitted in Part III of this article; however,
the ampacity of an individual feeder shall not be required to
be larger than the ampacity for the entire building.

This section shall not apply to portable classroom
buildings.

Table 220.86 Optional Method — Demand Factors for
Feeders and Service Conductors for Schools

Connected Load

Demand Factor

(%)

First 33 VA/m2
Plus,

(3 VA/ft2) at

100

Over 33 to 220

VA/m'Plus,

(3 to 20 VA/ft2) at

Remainder over

VA/m^

220

(20 VA/ft2) at

other loads that may be periodic in nature due to seasonal
or similar conditions.

(2) The maximum demand at 125 percent plus the new
load does not exceed the ampacity of the feeder or
rating of the service.

(3) The feeder has overcurrent protection in accordance
with 240.4, and the service has overload protection in
accordance with 230.90.

220.88 New Restaurants. Calculation of a service or
feeder load, where the feeder serves the total load, for a
new restaurant shall be permitted in accordance with Table
220.88 in lieu of Part III of this article.

The overload protection of the service conductors shall
be in accordance with 230.90 and 240.4.

Feeder conductors shall not be required to be of greater
ampacity than the service conductors.

Service or feeder conductors whose calculated load is
determined by this optional calculation shall be permitted
to have the neutral load determined by 220.61.

220.87 Determining Existing Loads. The calculation of
a feeder or service load for existing installations shall be
permitted to use actual maximum demand to determine the
existing load under all of the following conditions:

(1) The maximum demand data is available for a 1-year
period.

Exception: If the maximum demand data for a 1-year
period is not available, the calculated load shall be
permitted to be based on the maximum demand (measure of
average power demand over a IS-minute period)
continuously recorded over a minimum SO-day period
using a recording ammeter or power meter connected to
the highest loaded phase of the feeder or service, based on
the initial loading at the start of the recording. The
recording shall reflect the maximum demand of the feeder
or service by being taken when the building or space is
occupied and shall include by measurement or calculation
the larger of the heating or cooling equipment load, and

V. Farm Load Calculations

220.100 General. Farm loads shall be calculated in
accordance with Part V.

220.102 Farm Loads — Buildings and Other Loads.

(A) Dwelling Unit. The feeder or service load of a farm
dwelling unit shall be calculated in accordance with the
provisions for dwellings in Part III or IV of this article.
Where the dwelling has electric heat and the farm has
electric grain-drying systems, Part IV of this article shall
not be used to calculate the dwelling load where the
dwelling and farm loads are supplied by a common service.

(B) Other Than Dwelling Unit. Where a feeder or service
supplies a farm building or other load having two or more
separate branch circuits, the load for feeders, service
conductors, and service equipment shall be calculated in
accordance with demand factors not less than indicated in
Table 220.102.

Table 220.88 Optional Method — Permitted Load Calculations for Service and Feeder Conductors for New Restaurants

Total Connected
Load (kVA)

All Electric Restaurant
Calculated Loads (kVA)

Not All Electric Restaurant
Calculated Loads (kVA)

0-200
201-325
326-800
Over 800

80%
10% (amount over 200) + 160.0
50% (amount over 325) + 172.5
50% (amount over 800) + 410.0

100%
50% (amount over 200) + 200.0
45% (amount over 325) + 262.5
20% (amount over 800) + 476.3

Note: Add all electrical loads, including both heating and cooling loads, to calculate the total connected load. Select the one demand facto:
applies from the table, then multiply the total connected load by this single demand factor.

•

70-66

2010 California Electrical Code

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

225.4

Table 220.102 Method for Calculating Farm Loads for Other
Than Dwelling Unit

Table 225,2 Other Articles

Ampere Load at 240 Volts
Maximum

Demand Factor

(%)

Loads expected to operate

simultaneously, but not less than
125 percent full-load current of
the largest motor and not less
than the first 60 amperes of load

Next 60 amperes of all other loads

Remainder of other load

100

50
25

Equipment/Conductors

Article

220.103 Farm Loads — Total. Where supplied by a
common service, the total load of the farm for service
conductors and service equipment shall be calculated in
accordance with the farm dwelling unit load and demand
factors specified in Table 220.103. Where there is
equipment in two or more farm equipment buildings or for
loads having the same function, such loads shall be
calculated in accordance with Table 220.102 and shall be
permitted to be combined as a single load in Table 220.103
for calculating the total load.

Table 220.103 Method for Calculating Total Farm Load

Individual Loads Calculated in

Accordance with Table 220.102

Demand Factor (%)

Largest load

100

Second largest load

Third largest load

Remaining loads

Note: To this total load, add the load of the farm dwelling unit
calculated in accordance with Part III or IV of this article.
Where the dwelling has electric heat and the farm has electric
grain-drying systems, Part IV of this article shall not be used
to calculate the dwelling load.

Oiitside Branch Circuits and Feedm

225.1 Scope. This article covers requirements for outside
branch circuits and feeders run on or between buildings,
structures, or poles on the premises; and electrical
equipment and wiring for the supply of utilization
equipment that is located on or attached to the outside of
buildings, structures, or poles.

FPN: For additional information on wiring over 600 volts,
see ANSI C2-2007, National Electrical Safety Code.

225.2 Other Articles. Application of other articles,
including additional requirements to specific cases of
equipment and conductors, is shown in Table 225.2.

Branch circuits

210

Class 1, Class 2, and Class 3 remote-
control, signaling, and power-
limited circuits

725

Communications circuits

800

Community antenna television and
radio distribution systems

820

Conductors for general wiring

310

Electrically driven or controlled
irrigation machines

675

Electric signs and outhne lighting

600

Feeders

215

Fire alarm systems

760

Fixed outdoor electric deicing and
snow-melting equipment

426

Floating buildings

553

Grounding

250

Hazardous (classified) locations

500

Hazardous (classified) locations —
specific

510

Marinas and boatyards

555

Messenger supported wiring

396

Mobile homes, manufactured homes,
and mobile home parks

550

Open wiring on insulators

398

Over 600 volts, general

490

Overcurrent protection

240

Radio and television equipment

810

Services

230

Solar photovoltaic systems

690

Swimming pools, fountains, and
similar installations

680

Use and identification of grounded
conductors

200

I. General

225.3 Calculation of Loads 600 Volts, Nominal, or Less.

(A) Branch Circuits. The load on outdoor branch circuits
shall be as determined by 220.10.

(B) Feeders. The load on outdoor feeders shall be as
determined by Part III of Article 220.

225.4 Conductor Covering. Where within 3.0 m (10 ft) of

any building or structure other than supporting poles or
towers, open individual (aerial) overhead conductors shall
be insulated or covered. Conductors in cables or raceways,
except Type MI cable, shall be of the rubber-covered type
or thermoplastic type and, in wet locations, shall comply
with 310.8. Conductors for festoon lighting shall be of the
rubber-covered or thermoplastic type.

2010 California Electrical Code

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225.5

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

Exception: Equipment grounding conductors and
grounded circuit conductors shall be permitted to be bare
or covered as specifically permitted elsewhere in this Code,

225.5 Size of Conductors 600 Volts, Nominal, or Less.

The ampacity of outdoor branch-circuit and feeder
conductors shall be in accordance with 310.15 based on
loads as determined under 220.10 and Part III of Article
220.

225.6 Conductor Size and Support.

(A) Overhead Spans. Open individual conductors shall
not be smaller than the following:

(1) For 600 volts, nominal, or less, 10 AWG copper or 8
AWG aluminum for spans up to 15 m (50 ft) in length,
and 8 AWG copper or 6 AWG aluminum for a longer
span unless supported by a messenger wire

(2) For over 600 volts, nominal, 6 AWG copper or 4 AWG
aluminum where open individual conductors, and 8
AWG copper or 6 AWG aluminum where in cable

(B) Festoon Lighting. Overhead conductors for festoon
Hghting shall not be smaller than 12 AWG unless the
conductors are supported by messenger wires. In all spans
exceeding 12 m (40 ft), the conductors shall be supported
by messenger wire. The messenger wire shall be supported
by strain insulators. Conductors or messenger wires shall
not be attached to any fire escape, downspout, or plumbing
equipment.

225.7 Lighting Equipment Installed Outdoors.

(A) General. For the supply of lighting equipment installed
outdoors, the branch circuits shall comply with Article 210
and 225.7(B) through (D).

(B) Common Neutral. The ampacity of the neutral
conductor shall not be less than the maximum net
computed load current between the neutral Jc^dW<)| and
all ungrounded conductors connected to any one phase of
the circuit.

(C) 277 Volts to Ground. Circuits exceeding 120 volts,
nominal, between conductors and not exceeding 277 volts,
nominal, to ground shall be permitted to supply luminaires
for illumination of outdoor areas of industrial
establishments, office buildings, schools, stores, and other
commercial or public buildings where the luminaires are
not less than 900 mm (3 ft) from windows, platforms, fire
escapes, and the like.

(D) 600 Volts Between Conductors. Circuits exceeding
277 volts, nominal, to ground and not exceeding 600 volts,
nominal, between conductors shall be permitted to supply
the auxiliary equipment of electric-discharge lamps in
accordance with 210.6(D)(1).

225.10 Wiring on Buildings. The installation of outside
wiring on surfaces of buildings shall be permitted for circuits
of not over 600 volts Volts, nominal, as open wiring on
insulators, as multiconductor cable, as Type MC cable, as
IHilfJSJsSij ^s Type MI cable, as messenger-supported
wiring, in rigid metal conduit, in intermediate metal conduit,
in rigid nonmetallic conduit, in cable trays, as cablebus, in
wireways, in auxiliary gutters, in electrical metallic tubing,
in flexible metal conduit, in hquidtight flexible metal
conduit, in liquidtight flexible nonmetallic conduit, and in
busways. Circuits of over 600 volts, nominal, shall be
installed as provided in 300.37.

225.11 Circuit Exits and Entrances.

225.12 Open-Conductor Supports. Open conductors shall
be supported on glass or porcelain knobs, racks, brackets, or
strain insulators.

225.14 Open-Conductor Spacings.

(A) 600 Volts, Nominal, or Less. Conductors of 600 volts,
nominal, or less, shall comply with the spacings provided in
Table 230.51(C).

(B) Over 600 Volts, Nominal. Conductors of over 600
volts, nominal, shall comply with the spacings provided in
110.36 and 490.24.

(C) Separation from Other Circuits. Open conductors
shall be separated from open conductors of other circuits or
systems by not less than 100 mm (4 in.).

(D) Conductors on Poles. Conductors on poles shall have a
separation of not less than 300 mm (1 ft) where not placed
on racks or brackets. Conductors supported on poles shall
provide a horizontal climbing space not less than the
following:

(1) Power conductors below communications conductors —
750 mm (30 in.)

(2) Power conductors alone or above communications
conductors:

a. 300 volts or less — 600 mm (24 in.)

b. Over 300 volts — 750 mm (30 in.)

(3) Communications conductors below power conductors —
same as power conductors

(4) Communications conductors alone — no requirement

225.15 Supports over Buildings. Supports over a building
shall be in accordance with 230.29.

225.16 Attachment to Buildings.

(A) Point of Attachment. The point of attachment to a
building shall be in accordance with 230.26.

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2010 California Electrical Code

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

225.20

(B) Means of Attachment. The means of attachment to a
building shall be in accordance with 230.27.

225.17 Masts as Supports. Where a mast is used for the
support of final spans of feeders or branch circuits, it shall be
of adequate strength or be supported by braces or guys to
withstand safely the strain imposed by the overhead drop

Where raceway-type masts are used, all raceway fittings shall be
identified for use with masts. Only the feeder or branch-
circuit conductors specified within this section shall be
permitted to be attached to the feeder and/or branch-circuit
mast.

225.18 Clearance IgrjO^^fijfe^^

Overhead spans of open conductors and open
multiconductor cables of not over 600 volts, nominal, shall
have a clearance of not less than the following:

(1) 3.0m(10ft) — above finished grade, sidewalks, or fi"om
any platform or projection fi'om which they might be
reached where the voltage does not exceed 150 volts to
ground and accessible to pedestrians only

(2) 3.7 m (12 ft) — over residential property and driveways,
and those commercial areas not subject to truck traffic
where the voltage does not exceed 300 volts to ground

(3) 4.5 m (15 ft) — for those areas Hsted in the 3.7-m (12-ft)
classification where the voltage exceeds 300 volts to
ground

(4) 5.5 m (18 ft) — over public streets, alleys, roads, parking
areas subject to truck traffic, driveways on other than
residential property, and other land traversed by vehicles,
such as cultivated, grazing, forest, and orchard

225.19 Clearances from Buildings for Conductors of
Not over 600 Volts, Nominal.

(A) Above Roofs. Overhead spans of open conductors and
open multiconductor cables shall have a vertical clearance
of not less than 2.5 m (8 ft) above the roof surface. The
vertical clearance above the roof level shall be maintained
for a distance not less than 900 mm (3 ft) in all directions
from the edge of the roof

Exception No. I: The area above a roof surface subject to
pedestrian or vehicular traffic shall have a vertical
clearance from the roof surface in accordance with the
clearance requirements of 225.18.

Exception No. 2: Where the voltage between conductors
does not exceed 300, and the roof has a slope of 100 mm in
300 mm (4 in. in 12 in.) or greater, a reduction in
clearance to 900 mm (3 ft) shall be permitted.

Exception No. 3: Where the voltage between conductors
does not exceed 300, a reduction in clearance above only
the overhanging portion of the roof to not less than 450 mm
(18 in.) shall be permitted if (1) not more than 1.8 m (6 ft)
of the conductors, 1.2 m (4 ft) horizontally, pass above the
roof overhang and (2) they are terminated at a through-
the-roof raceway or approved support.

Exception No. 4: The requirement for maintaining the
vertical clearance 900 mm (3 ft) from the edge of the roof
shall not apply to the final conductor span where the
conductors are attached to the side of a building.

(B) From Nonbuilding or Nonbridge Structures. From
signs, chimneys, radio and television antennas, tanks, and
other nonbuilding or nonbridge structures, clearances —
vertical, diagonal, and horizontal — shall not be less than
900 mm (3 ft).

(D) Final Spans. Final spans of feeders or branch circuits
shall comply with 225.19(D)(1), (D)(2), and (D)(3).

(1) Clearance from Windows. Final spans to the building
they supply, or fi-om which they are fed, shall be permitted
to be attached to the building, but they shall be kept not
less than 900 mm (3 ft) fi-om windows that are designed to
be opened, and fi-om doors, porches, balconies, ladders,
stairs, fire escapes, or similar locations.

Exception: Conductors run above the top level of a
window shall be permitted to be less than the 900-mm (3 -ft)
requirement.

(2) Vertical Clearance. The vertical clearance of final
spans above, or within 900 mm (3 ft) measured
horizontally of, platforms, projections, or surfaces fi"om
which they might be reached shall be maintained in
accordance with 225. 1 8.

(3) BuUding Openings. The overhead branch-circuit and
feeder conductors shall not be installed beneath openings
through which materials may be moved, such as openings in
farm and commercial buildings, and shall not be installed
where they obstruct entrance to these buildings' openings.

(E) Zone for Fire Ladders. Where buildings exceed three
stories or 15 m (50 ft) in height, overhead lines shall be
arranged, where practicable, so that a clear space (or zone)
at least 1.8 m (6 ft) wide will be left either adjacent to the
buildings or beginning not over 2.5 m (8 ft) fi-om them to
facilitate the raising of ladders when necessary for fire
fighting.

225.20 Mechanical Protection of Conductors.

Mechanical protection of conductors on buildings,
structures, or poles shall be as provided for services in
230.50.

2010 California Electrical Code

70-69

225.21

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

225.21 Multiconductor Cables on Exterior Surfaces of
Buildings. Supports for multiconductor cables on exterior
surfaces of buildings shall be as provided in 230.51.

225.22 Raceways on Exterior Surfaces of Buildings or
Otiier Structures. Raceways on exteriors of buildings or
other structures shall be arranged to drain and shall be
raintight in wet locations.

225.24 Outdoor Lampliolders. Where outdoor
lampholders are attached as pendants, the connections to
the circuit wires shall be staggered. Where such
lampholders have terminals of a type that puncture the
insulation and make contact with the conductors, they shall
be attached only to conductors of the stranded type.

225.25 Location of Outdoor Lamps. Locations of lamps
for outdoor lighting shall be below all energized
conductors, transformers, or other electric utilization
equipment, unless either of the following apply:

(1) Clearances or other safeguards are provided for
relamping operations.

(2) Equipment is controlled by a disconnecting means that
can be locked in the open position.

225.26 Vegetation as Support. Vegetation such as trees
shall not be used for support of overhead conductor spans.

IL More Than One Building or Other Structure

225.30 Number of Supplies. Where more than one building
or other structure is on the same property and under single
management, each additional building or other structure that
is served by a branch circuit or feeder on the load side of the
service disconnecting means shall be supplied by only one
feeder or branch circuit unless permitted in 225.30(A)
through (E). For the purpose of this section, a multiwire
branch circuit shall be considered a single circuit.

(A) Special Conditions. Additional feeders or branch
circuits shall be permitted to supply the following:

(1) Fire pumps

(2) Emergency systems

(3) Legally required standby systems

(4) Optional standby systems

(5) Parallel power production systems

(6) Systems designed for connection to multiple sources
of supply for the purpose of enhanced rehability

(B) Special Occupancies. By special permission,

additional feeders or branch circuits shall be permitted for
either of the following:

(1) Muhiple-occupancy buildings where there is no space
available for supply equipment accessible to all
occupants

(2) A single building or other structure sufficiently large to
make two or more supplies necessary

(C) Capacity Requirements. Additional feeders or branch
circuits shall be permitted where the capacity requirements
are in excess of 2000 amperes at a supply voltage of 600
volts or less.

(D) Different Characteristics. Additional feeders or
branch circuits shall be permitted for different voltages,
frequencies, or phases or for different uses, such as control
of outside lighting from multiple locations.

(E) Documented Switching Procedures. Additional
feeders or branch circuits shall be permitted to supply
installations under single management where documented
safe switching procedures are established and maintained
for disconnection.

225.31 Disconnecting Means. Means shall be provided
for disconnecting all ungrounded conductors that supply or
pass through the building or structure.

225.32 Location. The disconnecting means shall be
installed either inside or outside of the building or structure
served or where the conductors pass through the building
or structure. The disconnecting means shall be at a readily
accessible location nearest the point of entrance of the
conductors. For the purposes of this section, the
requirements in 230.6 shall be utilized.

Exception No. 1: For installations under single
management, where documented safe switching procedures
are established and maintained for disconnection, and
where the installation is monitored by qualified
individuals, the disconnecting means shall be permitted to
be located elsewhere on the premises.

Exception No. 2: For buildings or other structures
qualifying under the provisions of Article 685, the
disconnecting means shall be permitted to be located
elsewhere on the premises.

Exception No. 3: For towers or poles used as lighting
standards, the disconnecting means shall be permitted to
be located elsewhere on the premises.

Exception No. 4: For poles or similar structures used only
for support of signs installed in accordance with Article
600, the disconnecting means shall be permitted to be
located elsewhere on the premises.

225.33 Maximum Number of Disconnects.

(A) General. The disconnecting means for each supply
permitted by 225.30 shall consist of not more than six
switches or six circuit breakers mounted in a single
enclosure, in a group of separate enclosures, or in or on a
switchboard. There shall bie no more than six disconnects
per supply grouped in any one location.

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2010 California Electrical Code

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

225.39

Exception: For the purposes of this section, disconnecting
means used solely for the control circuit of the ground-fault
protection system, or the control circuit of the power-
operated supply disconnecting means, installed as part of
the listed equipment, shall not be considered a supply
disconnecting means.

(B) Single-Pole Units. Two or three single-pole switches
or breakers capable of individual operation shall be
permitted on multiwire circuits, one pole for each
ungrounded conductor, as one multipole disconnect,
provided they are equipped with ^^mtl§|i| handle ties or a
master handle to disconnect all ungrounded conductors
with no more than six operations of the hand.

225.34 Grouping of Disconnects.

(A) General. The two to six disconnects as permitted in
225.33 shall be grouped. Each disconnect shall be marked
to indicate the load served.

Exception: One of the two to six disconnecting means
permitted in 225.33, where used only for a water pump
also intended to provide fire protection, shall be permitted
to be located remote from the other disconnecting means.

(B) Additional Disconnecting Means. The one or more
additional disconnecting means for fire pumps or for
emergency, legally required standby or optional standby
system permitted by 225.30 shall be installed sufficiently
remote from the one to six disconnecting means for normal
supply to minimize the possibility of simultaneous
interruption of supply.

225.35 Access to Occupants. In a multiple-occupancy
building, each occupant shall have access to the occupant's
supply disconnecting means.

Exception: In a multiple-occupancy building where
electric supply and electrical maintenance are provided by
the building management and where these are under
continuous building management supervision, the supply
disconnecting means supplying more than one occupancy
shall be permitted to be accessible to authorized
management personnel only.

225.36 Suitable for Service Equipment. The

disconnecting means specified in 225.31 shall be suitable
for use as service equipment

Exception: For garages and outbuildings on residential
property, a snap switch or a set of 3-way or 4-way snap
switches shall be permitted as the disconnecting means.

225.37 Identification. Where a building or structure has
any combination of feeders, branch circuits, or services
passing through it or supplying it, a permanent plaque or
directory shall be installed at each feeder and branch-circuit

disconnect location denoting all other services, feeders, or
branch circuits supplying that building or structure or
passing through that building or structure and the area
served by each.

Exception No. I: A plaque or directory shall not be
required for large-capacity multibuilding industrial
installations under single management, where it is ensured
that disconnection can be accomplished by establishing
and maintaining safe switching procedures.

Exception No. 2: This identification shall not be required
for branch circuits installed from a dwelling unit to a
second building or structure.

225.38 Disconnect Construction. Disconnecting means
shall meet the requirements of 225.38(A) through (D).

Exception: For garages and outbuildings on residential
property, snap switches or sets of 3-way or 4-way snap
switches shall be permitted as the disconnecting means.

(A) Manually or Power Operable. The disconnecting
means shall consist of either (1) a manually operable
switch or a circuit breaker equipped with a handle or other
suitable operating means or (2) a power-operable switch or
circuit breaker, provided the switch or circuit breaker can
be opened by hand in the event of a power failure.

(B) Simultaneous Opening of Poles. Each building or
structure disconnecting means shall simultaneously
disconnect all ungrounded supply conductors that it
controls from the building or structure wiring system.

(C) Disconnection of Grounded Conductor. Where the
building or structure disconnecting means does not
disconnect the grounded conductor from the grounded
conductors in the building or structure wiring, other means
shall be provided for this purpose at the location of
disconnecting means. A terminal or bus to which all
grounded conductors can be attached by means of pressure
connectors shall be permitted for this purpose.

In a multisection switchboard, disconnects for the
grounded conductor shall be permitted to be in any section
of the switchboard, provided any such switchboard section
is marked.

(D) Indicating. The building or structure disconnecting
means shall plainly indicate whether it is in the open or
closed position.

225.39 Rating of Disconnect. The feeder or branch-circuit
disconnecting means shall have a rating of not less than the
SSiliMi 1^^*^ to be suppHed, determined in accordance
with Parts I and II of Article 220 for branch circuits, Part
III or IV of Article 220 for feeders, or Part V of Article 220
for farm loads. [pS^e;^^.^|^?2%fflSL3^1il^

2010 California Electrical Code

70-71

225.40

ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS

discoimectmg mean^^

circuit breaker, as permitted by 22l33, combmmg the!

ratmgs of ail the switches or circuit breakers for

deteitnimng the rating of the disconnecting means shall be;

germitteA In no case shaU the tat^^

spSdiiecl in 22539{A)r(BI ^^

(A) One-Circuit Installation. For installations to supply
only limited loads of a single branch circuit, the branch
circuit disconnecting means shall have a rating of not less
than 15 amperes.

(B) Two-Circuit Installations. For installations consisting
of not more than two 2-wire branch circuits, the feeder or
branch-circuit disconnecting means shall have a rating of
not less than 30 amperes.

(C) One-Family Dwelling. For a one-family dwelling, the
feeder disconnecting means shall have a rating of not less
than 100 amperes, 3-wire.

(D) All Others. For all other installations, the feeder or
branch-circuit disconnecting means shall have a rating of
not less than 60 amperes.

225.40 Access to Overcurrent Protective Devices.

Where a feeder overcurrent device is not readily accessible,
branch-circuit overcurrent devices shall be installed on the
load side, shall be mounted in a readily accessible location,
and shall be of a lower ampere rating than the feeder
overcurrent device.

III. Over 600 Volts

225.50 Sizing of Conductors. The sizing of conductors
over 600 volts shall be in accordance with 210.19(B) for
branch circuits and 215.2(B) for feeders.

225.51 Isolating Switches. Where oil switches or air, oil,
vacuum, or sulfur hexafluoride circuit breakers constitute a
building disconnecting means, an isolating switch with
visible break contacts and meeting the requirements of
230.204(B), (C), and (D) shall be installed on the supply
side of the disconnecting means and all associated
equipment.

Exception: The isolating switch shall not be required
where the disconnecting means is mounted on removable
truck panels or metal-enclosed switchgear units that
cannot be opened unless the circuit is disconnected and
that, when removed from the normal operating position,
automatically disconnect the circuit breaker or switch from
all energized parts.

225.52 Location. A building or structure disconnecting
means shall be located in accordance with 225.32, or it
shall be electrically operated by a similarly located remote-
control device.

225.53 Type. Each building or structure disconnect shall
simultaneously disconnect all ungrounded supply
conductors it controls and shall have a fault-closing rating
not less than the maximum available short-circuit current
available at its supply terminals.

Where fused switches or separately mounted fuses are
installed, the fuse characteristics shall be permitted to
contribute to the fault closing rating of the disconnecting
means.

225.60 Clearances over Roadways, Walkways, Rail,
Water, and Open Land.

(A) 22 kV, Nominal, to Ground or Less. The clearances
over roadways, walkways, rail, water, and open land for
conductors and Hve parts up to 22 kV, nominal, to ground
or less shall be not less than the values shown in Table
225.60.

Table 225.60 Clearances over Roadways, Walkways, Rail,
Water, and Open Land

Clearance

Location

Open land subject to vehicles,
cultivation, or grazing

5.6

18.5

Roadways, driveways, parking lots,
and alleys

5.6

18.5

Walkways

4.1

13.5

Rails

8.1

26.5

Spaces and ways for pedestrians and
restricted traffic

4.4

14.5

Water areas not suitable for boating

5.2

17.0

(B) Over 22 kV Nominal to Ground. Clearances for the
categories shown in Table 225.60 shall be increased by 10
mm (0.4 in.) per kV above 22,000 volts.

(C) Special Cases. For special cases, such as where
crossings will be made over lakes, rivers, or areas using
large vehicles such as mining operations, specific designs
shall be engineered considering the special circumstances
and shall be approved by the authority having jurisdiction.

FPN: For additional information, see ANSI C2-2007,
National Electrical Safety Code.

225.61 Clearances over Buildings and Other Structures.

(A) 22 kV Nominal to Ground or Less. The clearances
over buildings and other structures for conductors and live
parts up to 22 kV, nominal, to ground or less shall be not
less than the values shown in Table 225.61 .

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2010 California Electrical Code

ARTICLE 230 - SERVICES

230.2

Table 225.61 Clearances over Buildings and Other Structures

Clearance from

Conductors or Live

Parts from:

Horizontal

Vertical

Building walls, 2.3 7.5 — —

projections, and
windows

Balconies, catwalks, 2.3 7.5 4.1 13.5

and similar areas
accessible to
people

Over or under roofs or — — 3.8 12.5

projections not
readily accessible
to people

Over roofs accessible — — 4.1 13.5

to vehicles but not
trucks

Over roofs accessible — — 5.6 18.5

to trucks

Other structures 2.3 7.5 — —

(B) Over 22 kV Nominal to Ground. Clearances for the
categories shown in Table 225.61 shall be increased by 10
mm (0.4 in.) per kV above 22,000 volts.

FPN: For additional information, see ANSI C2-2007,
National Electrical Safety Code.

230.1 Scope. This article covers service conductors and
equipment for control and protection of services and their
installation requirements.

FPN: See F^fmjl

I. General

230.2 Number of Services. A building or other structure
served shall be supplied by only one service unless
permitted in 230.2(A) through (D). For the purpose of
230.40, Exception No. 2 only, underground sets of
conductors, 1/0 AWG and larger, running to the same
location and connected together at their supply end but not
connected together at their load end shall be considered to
be supplying one service.

(A) Special Conditions. Additional services shall be
permitted to supply the following:

(1) Fire pumps

(2) Emergency systems

(3) Legally required standby systems

General Part \

Overhead Service-Drop Conductors Part tl

Underground Service-Lateral Conductors Part III

Service-Entrance Conductors Part iV

Service Equipment— General Part V

Ser^^ce Equipment— Disconnecting Means Part VI

Service Equipment — Overcurrent Protection Part VI I

Services Exceeding BOO Volts, Nominal Part VIII

Source

Overhead
last pole

Underground
Street main

Part 11 Service drop
230.24 Clearances

Service head

Service lateral Part ill

Depth of burial 230.49
and protection

Terminal box,
meter, or other

enclosure

Service-entrance
conductors

Part IV

Service equipment— general
Grounding and bonding

PartV
Article 250

Disconnecting means

Part VI

Overcurrent protection

Pail Vli

Branch circuits
Feeders

Articles 210, 225
Articles 215. 225

iigure 230,1 ServicesJ

(4) Optional standby systems

(5) Parallel power production systems

(6) Systems designed for connection to multiple sources of
supply for the purpose of enhanced rehability

(B) Special Occupancies. By special permission,
additional services shall be permitted for either of the
following:

(1) Multiple-occupancy buildings where there is no
available space for service equipment accessible to all
occupants

(2) A single building or other structure sufficiently large to
make two or more services necessary

(1) Where the capacity requirements are in excess of 2000
amperes at a supply voltage of 600 volts or less

(2) Where the load requirements of a single-phase
installation are greater than the serving agency
normally supplies through one service

(3) By special permission

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230.3

ARTICLE 230 - SERVICES

(D) Different Characteristics. Additional services shall be
permitted for different voltages, frequencies, or phases, or
for different uses, such as for different rate schedules.

(E) Identification. Where a building or structure is
supplied by more than one service, or any combination of
branch circuits, feeders, and services, a permanent plaque
or directory shall be installed at each service disconnect
location denoting all other services, feeders, and branch
circuits supplying that building or structure and the area
served by each. See 225.37.

230.3 One Building or Other Structure Not to Be
Supplied Through Another. Service conductors
supplying a building or other structure shall not pass
through the interior of another building or other structure.

230.6 Conductors Considered Outside the Building.

Conductors shall be considered outside of a building or
other structure under any of the following conditions:

(1) Where installed under not less than 50 mm (2 in.) of
concrete beneath a building or other structure

(2) Where installed within a building or other structure in a
raceway that is encased in concrete or brick not less
than 50mm (2 in.) thick '

(3) Where installed in any vault that meets the construction
requirements of Article 450, Part III

(4) Where installed in conduit and under not less than 450
mm (18 in.) of earth beneath a building or other
structure

230.7 Other Conductors in Raceway or Cable.

Conductors other than service conductors shall not be
installed in the same service raceway or service cable.

Exception No. 1: Grounding conductors and bonding
jumpers.

Exception No. 2: Load management control conductors
having overcurrent protection.

230.8 Raceway Seal. Where a service raceway enters a
building or structure from an underground distribution
system, it shall be sealed in accordance with 300.5(G).
Spare or unused raceways shall also be sealed. Sealants
shall be identified for use with the cable insulation, shield,
or other components.

230.9 Clearances on Buildings. Service conductors and
final spans shall comply with 230.9(A), (B), and (C).

(A) Clearances. Service conductors installed as open
conductors or multiconductor cable without an overall
outer jacket shall have a clearance of not less than 900 mm
(3 ft) from windows that are designed to be opened, doors,
porches, balconies, ladders, stairs, fire escapes, or similar
locations.

Exception: Conductors run above the top level of a
window shall be permitted to be less than the 900-mm (3-ft)
requirement.

(B) Vertical Clearance. The vertical clearance of final
spans above, or within 900 mm (3 ft) measured
horizontally of, platforms, projections, or surfaces from
which they might be reached shall be maintained in
accordance with 230.24(B).

(C) Building Openings. Overhead service conductors shall
not be installed beneath openings through which materials
may be moved, such as openings in farm and commercial
buildings, and shall not be installed where they obstruct
entrance to these building openings.

230.10 Vegetation as Support. Vegetation such as trees
shall not be used for support of overhead service conductors.

II. Overhead Service-Drop Conductors

Individual conductors

230.22 Insulation or Covering.

shall be insulated or covered.

Exception: The grounded conductor of a multiconductor
cable shall be permitted to be bare.

230.23 Size and Rating.

(A) General. Conductors shall have sufficient ampacity to
carry the current for the load as calculated in accordance
with Article 220 and shall have adequate mechanical
strength.

(B) Minimum Size. The conductors shall not be smaller
than 8 AWG copper or 6 AWG aluminum or copper-clad
aluminum.

Exception: Conductors supplying only limited loads of a
single branch circuit — such as small polyphase power,
controlled water heaters, and similar loads — shall not be
smaller than 12 A WG hard-drawn copper or equivalent.

230.24 Clearances. Service-drop conductors shall not be
readily accessible and shall comply with 230.24(A) through

(D) for services not over 600 volts, nominal.

(A) Above Roofs. Conductors shall have a vertical
clearance of not less than 2.5 m (8 ft) above the roof
surface. The vertical clearance above the roof level shall be
maintained for a distance of not less than 900 mm (3 ft) in
all directions from the edge of the roof

•

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2010 California Electrical Code

ARTICLE 230 - SERVICES

230.33

Exception No. 2: Where the voltage between conductors
does not exceed 300 and the roof has a slope of 100 mm in
300 mm (4 in. in 12 in.) or greater, a reduction in
clearance to 900 mm (3 ft) shall be permitted.

Exception No. 3: Where the voltage between conductors
does not exceed 300, a reduction in clearance above only
the overhanging portion of the roof to not less than 450 mm
(18 in.) shall be permitted if (1) not more than 1.8 m (6 ft)
of service-drop conductors, 1.2 m (4 ft) horizontally, pass
above the roof overhang, and (2) they are terminated at a
through- the-roof raceway or approved support.

FPN: See 230.28 for mast supports.

Exception No. 4: The requirement for maintaining the
vertical clearance 900 mm (3 ft) from the edge of the roof
shall not apply to the final conductor span where the
service drop is attached to the side of a building.

(B) Vertical Clearance for Servlce-Brop CpnduC

Service-drop conductors, where not in excess of 600 volts,
nominal, shall have the following minimum clearance from
final grade:

(1) 3.0 m (10 ft) — at the electrical service entrance to
buildings, also at the lowest point of the drip loop of
the building electrical entrance, and above areas or
sidewalks accessible only to pedestrians, measured
from final grade or other accessible surface only for
service-drop cables supported on and cabled together
with a grounded bare messenger where the voltage
does not exceed 1 50 vohs to ground

(2) 3.7 m (12 ft) — over residential property and
driveways, and those commercial areas not subject to
truck traffic where the vohage does not exceed 300
volts to ground

(3) 4.5 m (15 ft) — for those areas hsted in the 3.7-m (12-
ft) classification where the voltage exceeds 300 volts
to ground

(4) 5.5 m (18 ft) — over public streets, alleys, roads,
parking areas subject to truck traffic, driveways on
other than residential property, and other land such as
cuhivated, grazing, forest, and orchard

(D) Clearance from Swimming Pools. See 680.8.

230.26 Point of Attachment. The point of attachment of
the service-drop conductors to a building or other structure
shall provide the minimum clearances as specified in 230.9
and 230.24. In no case shall this point of attachment be less
than 3.0 m (10 ft) above finished grade.

230.27 Means of Attachment. Multiconductor cables
used for service drops shall be attached to buildings or
other structures by fittings identified for use with service
conductors. Open conductors shall be attached to fittings
identified for use with service conductors or to
noncombustible, nonabsorbent insulators securely attached
to the building or other structure.

230.28 Service Masts as Supports. Where a service mast
is used for the support of service-drop conductors, it shall
be of adequate strength or be supported by braces or guys
to withstand safely the strain imposed by the service drop.
Where raceway-type service masts are used, all raceway
fittings shall be identified for use with service masts. Only
power service-drop conductors shall be permitted to be
attached to a service mast.

230.29 Supports over Buildings. Service-drop conductors
passing over a roof shall be securely supported by
substantial structures. Where pracficable, such supports
shall be independent of the building.

III. Underground Service-Lateral Conductors

230.30 Insulation. Service-lateral conductors shall be
insulated for the applied voltage.

Exception: A grounded conductor shall be permitted to be
uninsulated as follows:

(1) Bare copper used in a raceway.

(2) Bare copper for direct burial where bare copper is
judged to be suitable for the soil conditions.

(3) Bare copper for direct burial without regard to soil
conditions where part of a cable assembly identified for
underground use.

(4) Aluminum or copper-clad aluminum without individual
insulation or covering where part of a cable assembly identified
for underground use in a raceway or for direct burial

230.31 Size and Rating.

(A) General. Service-lateral conductors shall have
sufficient ampacity to carry the current for the load as
calculated in accordance with Article 220 and shall have
adequate mechanical strength.

230.32 Protection Against Damage. Underground
service-lateral conductors shall be protected against
damage in accordance with 300.5. Service-lateral
conductors entering a building shall be installed in
accordance with 230.6 or protected by a raceway wiring
method identified in 230.43.

230.33 Spliced Conductors. Service-lateral conductors
shall be permitted to be spliced or tapped in accordance
with 110.14, 300.5(E), 300.13, and 300.15.

2010 California Electrical Code

70-75

230.40

ARTICLE 230 - SERVICES

be determined from 310.15. The maximum allowable
current of busways shall be that value for which the
busway has been listed or labeled.

(1) The sum of the noncontinuous loads plus 125 percent
of continuous loads

(2) The sum of the noncontinuous load plus the
continuous load if the service-entrance conductors
terminate in an overcurrent device where both the
overcurrent device and its assembly are listed for
operation at 1 00 percent of their rating

(B) Specific Installations. In addition to the requirements
of 230.42(A), the minimum ampacity for ungrounded
conductors for specific installations shall not be less than
the rating of the service disconnecting means specified in
230.79(A) through (D).

250.24(C).

230.43 Wiring Methods for 600 Volts, Nominal, or Less.

Service-entrance conductors shall be installed in
accordance with the applicable requirements of this Code
covering the type of wiring method used and shall be
imited to the following methods:

1) Open wiring on insulators

2) Type IGS cable

3) Rigid metal conduit

4) Intermediate metal conduit

5) Electrical metallic tubing

6) Electrical nonmetaUic tubing (ENT)

7) Service-entrance cables

8) Wireways

9) Busways

10) Auxiliary gutters

1 1) Rigid nonmetallic conduit

12) Cablebus

13) Type MC cable

14) Mineral-insulated, metal-sheathed cable

15) Flexible metal conduit not over 1.8 m (6 ft) long or
liquidtight flexible metal conduit not over 1.8 m (6 ft)
long between raceways, or between raceway and
service equipment, with equipment bonding jumper
routed with the flexible metal conduit or the liquidtight
flexible metal conduit according to the provisions of
250.102(A), (B),(C), and (E)

I^ W, driV,;o|:iitoic^ Ampacity shall (16) Liquidtight flexible nonmetallic conduit

IV. Service-Entrance Conductors

230.40 Number of Service-Entrance Conductor Sets.

Each service drop or lateral shall supply only one set of
service-entrance conductors.

Exception No. 1: A building mth /more than one
occupancy shall be permitted to have one set of service-
entrance conductors for each service, as defined in 230.2,
run to each occupancy or group of occupancies.

Exception No. 2: Where two to six service disconnecting
means in separate enclosures are grouped at one location
and supply separate loads from one service drop or lateral,
one set of service- entrance conductors shall be permitted to
supply each or several such service equipment enclosures.

Exception No. 3: A single-family dwelling unit and a
separate structure shall be permitted to have one set of
service-entrance conductors run to each from a single
service drop or lateral.

Exception No. 4: A two-family dwelling or a multifamily
dwelling shall be permitted to have one set of service-
entrance conductors installed to supply the circuits covered
in 210.25.

Exception No. 5: One set of service-entrance conductors
connected to the supply side of the normal service
disconnecting means shall be permitted to supply each or
several systems covered by 230.82(5) or 230.82(6).

230.41 Insulation of Service-Entrance Conductors.

Service-entrance conductors entering or on the exterior of
buildings or other structures shall be insulated.

Exception: A grounded conductor shall be permitted to be
uninsulated as follows:

(!) Bare copper used in a raceway or part of a service
cable assembly.

(2) Bare copper for direct burial where bare copper is
Judged to be suitable for the soil conditions.

(3) Bare copper for direct burial without regard to soil
conditions where part of a cable assembly identified for
underground use.

(4) Aluminum or copper-clad aluminum without
individual insulation or covering where part of a cable
assembly or identified for underground use in a raceway, or
for direct burial.

(5) Bare conductors used in an auxiliary gutter.

230.42 Minimum Size and Rating.

(A) General. The ampacity of the service-entrance
conductors before the application of any adjustment or
correction factors shall not be less than either (A)(1) or
Loads shall be determined in accordance with Part

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2010 California Electrical Code

ARTICLE 230 - SERVICES

230.51

230.44 Cable Trays. Cable tray systems shall be
permitted to support service-entrance conductors. Cable
trays used to support service-entrance conductors shall
contain only service -entrance conductors.

Exception: Conductors, other than service-entrance
conductors, shall be permitted to be installed in a cable
tray with service-entrance conductors, provided a solid
fixed barrier of a material compatible with the cable tray is
installed to separate the service-entrance conductors from
other conductors installed in the cable tray. Cable trays,
shall beMeniified with permanently affixed labels with the
}yprdingj";Seiyice-Entrance Cdnduci6rs,f The labels shall
be located so as to be visible after instdlidtibn and placea
'sa thai the service^entrance conductors may be readily
trqcedfi^iqugh the entire length of the cjahle^h^

230.46 Spliced Conductors. Service-entrance conductors
shall be permitted to be spHced or tapped in accordance
with 1 10.14, 300.5(E), 300.13, and 300.15.

230.50 Protection Against Physical Damage.

|(A)j Underground Seryic e-Entrajtfee: CondnfetQ t%.
Underground service-entrance conductors shall be
protected against physical damage in accordance with
300.5.

(Bll^^iWI; ;;fJ^Ii^»' \Service-p»traiie^: idoMiic^^ oth^

^er^i!D*6refito^ conduct^irs;^^; ;.^igl|^;3!3^
&ftj^(&j]jlDJ^^ shall be protected against

physical damage as specified in '§M^:^^^MkMM)i?)\

(1) Service Cables. Service cables, where subject to
physical, damage, shall be protected by any of the
following:

(1) Rigid metal conduit

(2) Intermediate metal conduit

(3) Schedule 80 Pf q conduit

(4) Electrical metallic tubing

(5) Other approved means

(2) Other Than Service Cable. Individual open
conductors and cables, other than service cables, shall not
be installed within 3.0 m (10 ft) of grade level or where
exposed to physical damage.

Exception: Type MI and Type MC cable shall be permitted
within 3,0 m (10 ft) of grade level where not exposed to
physical damage or where protected in accordance with
300, 5(D),

230.51 Mounting Supports. Cables or individual open
service conductors shall be supported as specified in
230.51(A), (B), or (C).

(A) Service Cables. Service cables shall be supported by
straps or other approved means within 300 mm (12 in.) of
every service head, gooseneck, or connection to a raceway
or enclosure and at intervals not exceeding 750 mm (30
in.).

(B) Other Cables. Cables that are not approved for
mounting in contact with a building or other structure shall
be mounted on insulating supports installed at intervals not
exceeding 4.5 m (15 ft) and in a manner that maintains a
clearance of not less than 50 mm (2 in.) from the surface
over which they pass.

(C) Individual Open Conductors. Individual open
conductors shall be installed in accordance with Table
230.51(C). Where exposed to the weather, the conductors
shall be mounted on insulators or on insulating supports
attached to racks, brackets, or other approved means.
Where not exposed to the weather, the conductors shall be
mounted on glass or porcelain knobs.

230.52 Individual Conductors Entering Buildings or Other
Structures. Where individual open conductors enter a
building or other structure, they shall enter through roof
bushings or through the wall in an upward slant through
individual, noncombustible, nonabsorbent insulating tubes.
Drip loops shall be formed on the conductors before they enter
the tubes.

230.53 Raceways to Drain. Where exposed to the weather,
raceways enclosing service-entrance conductors shall be
^m^la for i|se in w and arranged to drain. Where
embedded in masonry, raceways shall be arranged to drain.

230.54 Overhead Service Locations.

(A) Service Head. Service raceways shall be equipped with a
service head at jthe point of connection to ^ervice-drop
conductors. [The -service head sMl Spmply;: \^^ the

20 1 California Electrical Code

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230.56

ARTICLE 230 - SERVICES

Table 230.51(C) Supports

Maximum Distance Between Supports
m ft

Minimum Clearance

Between Conductors

From Surface

Maximum Volts

in.

mm in.

600

2.7

150

50 2

600

4.5

300

50 2

300

1.4

4'/2

50 2

600*

1.4*

4^2*

65*

2^/2*

25* 1*

*Where not exposed to weather.

(B) Service Cable Equipped with Service Head or
Gooseneck. Service cables shall be equipped with a
service head; the service head shall comply :m^
reqiairement for fittings in 314. 1 5,

Exception: Type SE cable shall be permitted to be formed
in a gooseneck and taped with a self-sealing weather-
resistant thermoplastic,

(C) Service Heads and Goosenecks Above Service-
Drop Attachment. Service heads and goosenecks in
service-entrance cables shall be located above the point of
attachment of the service-drop conductors to the building
or other structure.

Exception: Where it is impracticable to locate the service
head or gooseneck above the point of attachment, the
service head or gooseneck location shall be permitted not
farther than 600 mm (24 in.) from the point of attachment.

(D) Secured. Service cables shall be held securely in
place.

(E) Separately Bushed Openings. Service heads shall
have conductors of different potential brought out through
separately bushed openings.

Exception: For jacketed multiconductor service cable
without splice.

(F) Drip Loops. Drip loops shall be formed on individual
conductors. To prevent the entrance of moisture, service-
entrance conductors shall be connected to the service-
drop conductors either (1) below the level of the service
head or (2) below the level of the termination of the
service-entrance cable sheath.

(G) Arranged That Water Will Not Enter Service
Raceway or Equipment. Service-drop conductors and
service-entrance conductors shall be arranged so that
water will not enter service raceway or equipment.

230.56 Service Conductor with the Higher Voltage to
Ground. On a 4-wire, deha-connected service where the
midpoint of one phase winding is grounded, the service
conductor having the higher phase voltage to ground shall
be durably and permanently marked by an outer finish

that is orange in color, or by other effective means, at
each termination or junction point.

V. Service Equipment — General

230.62 Service Equipment — Enclosed or Guarded.

Energized parts of service equipment shall be enclosed
as specified in 230.62(A) or guarded as specified in
230.62(B).

(A) Enclosed. Energized parts shall be enclosed so that
they will not be exposed to accidental contact or shall
be guarded as in 230.62(B).

(B) Guarded. Energized parts that are not enclosed
shall be installed on a switchboard, panelboard, or
control board and guarded in accordance with 110.18
and 110.27. Where energized parts are guarded as
provided in 110.27(A)(1) and (A)(2), a means for
locking or sealing doors providing access to energized
parts shall be provided.

230.66 Marking. Service equipment rated at 600 volts
or less shall be marked to identify it as being suitable
for use as service equipment. Individual meter socket
enclosures shall not be considered service equipment.

VI. Service Equipment — Disconnecting Means

230.70 General. Means shall be provided to
disconnect all conductors in a building or other
structure from the service-entrance conductors.

(A) Location. The service disconnecting means shall
be installed in accordance with 230.70(A)(1), (A)(2),
and (A)(3).

(1) Readily Accessible Location. The service
disconnecting means shall be installed at a readily
accessible location either outside of a building or
structure or inside nearest the point of entrance of the
service conductors.

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ARTICLE 230 - SERVICES

230.79

(2) Bathrooms. Service disconnecting means shall not be
installed in bathrooms.

(3) Remote Control. Where a remote control device(s) is
used to actuate the service disconnecting means, the service
disconnecting means shall be located in accordance with
230.70(A)(1).

(B) Marking. Each service disconnect shall be
permanently marked to identify it as a service disconnect.

(C) Suitable for Use. Each service disconnecting means
shall be suitable for the prevailing conditions. Service
equipment installed in hazardous (classified) locations shall
comply v^ith the requirements of Articles 500 through 517.

230.71 Maximum Number of Disconnects.

(A) General. The service disconnecting means for each
service permitted by 230.2, or for each set of service-
entrance conductors permitted by 230.40, Exception No. 1,
3, 4, or 5, shall consist of not more than six switches or sets
of circuit breakers, or a combination of not more than six
switches and sets of circuit breakers, mounted in a single
enclosure, in a group of separate enclosures, or in or on a
switchboard. There shall be not more than six sets of
disconnects per service grouped in any one location.

For the purpose of this section, disconnecting means
ittstalfed^ part of listed eqiiipment a used solely for the
fpnowmg shall iiot be comidered a service discdimectirig

(1) Power monitoring equipment

(2) Surge-protective device(s)

(3) Control circuit of the ground-fault protection system

(4) Power-operable service disconnecting means

(B) Single-Pole Units. Two or three single-pole switches
or breakers, capable of individual operation, shall be
permitted on multiwire circuits, one pole for each
ungrounded conductor, as one multipole disconnect,
provided they are equipped with ideatified handle ties or a
master handle to disconnect all conductors of the service
with no more than six operations of the hand.

FPN: See 408.36, £xcepti<m Ho. 1 and Bxception Ho. 3, for

service equipment in certain panelboards, and see 430.95
for service equipment in motor control centers.

230.72 Grouping of Disconnects.

(A) General. The two to six disconnects as permitted in
230.71 shall be grouped. Each disconnect shall be marked
to indicate the load served.

Exception: One of the two to six service disconnecting means
permitted in 230.71, where used only for a water pump also
intended to provide fire protection, shall be permitted to he
located remote from the other disconnecting means.

(B) Additional Service Disconnecting Means. The one or

more additional service disconnecting means for fire
pumps, emergency systems, legally required standby, or
optional standby services permitted by 230.2 shall be
installed remote from the one to six service disconnecting
means for normal service to minimize the possibility of
simultaneous interruption of supply,

(C) Access to Occupants. In a multiple-occupancy
building, each occupant shall have access to the occupant's
service disconnecting means.

Exception: In a multiple-occupancy building where
electric service and electrical maintenance are provided by
the building management and where these are under
continuous building management supervision, the service
disconnecting means supplying more than one occupancy
shall be permitted to be accessible to authorized
management personnel only.

230.74 Simultaneous Opening of Poles. Each service
disconnect shall simultaneously disconnect all ungrounded
service conductors that it controls from the premises wiring
system.

230.75 Disconnection of Grounded Conductor. Where
the service disconnecting means does not disconnect the
grounded conductor from the premises wiring, other means
shall be provided for this purpose in the service equipment.
A terminal or bus to which all grounded conductors can be
attached by means of pressure connectors shall be
permitted for this purpose. In a multisection switchboard,
disconnects for the grounded conductor shall be permitted
to be in any section of the switchboard, provided any such
switchboard section is marked.

230.76 Manually or Power Operable. The service
disconnecting means for ungrounded service conductors
shall consist of one of the following:

(1) A manually operable switch or circuit breaker equipped
with a handle or other suitable operating means

(2) A power-operated switch or circuit breaker, provided
the switch or circuit breaker can be opened by hand in
the event of a power supply failure

230.77 Indicating. The service disconnecting means shall
plainly indicate whether it is in the open or closed position.

230.79 Rating of Service Disconnecting Means. The

service disconnecting means shall have a rating not less
than the calculated load to be carried, determined in
accordance with Part ID, IVi or V of Article 220, as
applicable; In no case shall the rating be lower than
specified in 230.79(A), (B), (C), or (D).

(A) One-Circuit Installations. For installations to
supply only limited loads of a single branch circuit, the
service disconnecting means shall have a rating of not
less than 15 amperes^

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70-79

230.80

ARTICLE 230 - SERVICES

(B) Two-Circuit Installations. For installations
consisting of not more than two 2-wire branch circuits,
the service disconnecting means shall have a rating of
not less than 30 amperes.

(C) One-Family Dwellings. For a one-family dwelling,
the service disconnecting means shall have a rating of
not less than 100 amperes, 3 -wire.

(D) All Others. For all other installations, the service
disconnecting means shall have a rating of not less than
60 amperes.

230.80 Combined Rating of Disconnects. Where the

service disconnecting means consists of more than one
switch or circuit breaker, as permitted by 230.71, the
combined ratings of all the switches or circuit breakers
used shall not be less than the rating required by 230.79.

230.81 Connection to Terminals. The service
conductors shall be connected to the service
disconnecting means by pressure connectors, clamps, or
other approved means. Connections that depend on
solder shall not be used.

230.82 Equipment Connected to the Supply Side of
Service Disconnect. Only the following equipment
shall be permitted to be connected to the supply side of
the service disconnecting means:

(1) Cable limiters or other current-limiting devices.

(2) Meters and meter sockets nominally rated not in excess of
600 volts, provided all metal housings and service
enclosures are grounded k m:cardance witii Part VH and
bonded in accoixjancc with Part V of Article 250;

(3) Meter disconnect switches nominally rated not in excess of
600 volts that have a short-circuit current rating equal to or
greater than the available short-circuit current, provided all
metal housings and service enclosures are grounded in
accordance with Part VH and bonded in aca)rda2ice m&i
Part V of Articte 250. A met^ disconnect switch diall Ije
capable of intem^tkig the load servedi

(4) Instrument transformers (current and voltage), impedance
shunts, load management devices, mtgQ arresters, md
Type 1 surge-protective device^,

(5) Taps used only to supply load management devices,
circuits for standby power systems, fire pump equipment,
and fire and sprinkler alarms, if provided with service
equipment and installed in accordance with requirements
for service-entrance conductors.

(6) Solar photovoltaic systems, fuel cell systems, or
interconnected electric power production sources.

(7) Control circuits for power-operable service disconnecting

means, if suitable overcurrent protection and disconnecting
means are provided.

(8) Ground-fault protection systems or Type 2 surge-
protective devices, where installed as part of listed
equipment, if suitable overcurrent protection and
disconnecting means are provided.

VIL Service Equipment — Overcurrent Protection

230.90 Where Required. Each ungrounded service
conductor shall have overload protection.

(A) Ungrounded Conductor. Such protection shall be
provided by an overcurrent device in series with each
ungrounded service conductor that has a rating or setting
not higher than the allowable ampacity of the conductor. A
set of fuses shall be considered all the fuses required to
protect all the ungrounded conductors of a circuit. Single-
pole circuit breakers, grouped in accordance with
230.71(B), shall be considered as one protective device.

Exception No. 1: For motor-starting currents, ratings that
comply with 430.52, 430.62, and 430.63 shall be permitted.

Exception No. 2: Fuses and circuit breakers with a rating
or setting that complies with 240.4(B) or (C) and 240.6
shall be permitted.

Exception No. 3: Two to six circuit breakers or sets of
fuses shall be permitted as the overcurrent device to
provide the overload protection. The sum of the ratings of
the circuit breakers or fuses shall be permitted to exceed
the ampacity of the service conductors, provided the
calculated load does not exceed the ampacity of the service
conductors.

Exception No. 4: Overload protection for fire pump supply
conductors shall comply with 695.4(B)(1).

Exception No. 5: Overload protection for 120/240-volt, 3-
wire, single-phase dwelling services shall be permitted in
accordance with the requirements of 310.15(B)(6).

(B) Not in Grounded Conductor. No overcurrent device
shall be inserted in a grounded service conductor except a
circuit breaker that simultaneously opens all conductors of
the circuit.

230.91 Location. The service overcurrent device shall be
an integral part of the service disconnecting means or shall
be located immediately adjacent thereto.

230.92 Loclied Service Overcurrent Devices. Where the

service overcurrent devices are locked or sealed or are not
readily accessible to the occupant, branch-circuit
overcurrent devices shall be installed on the load side, shall
be mounted in a readily accessible location, and shall be of
lower ampere rating than the service overcurrent device.

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ARTICLE 230 - SERVICES

230.200

230.93 Protection of Specific Circuits. Where necessary
to prevent tampering, an automatic overcurrent device that
protects service conductors supplying only a specific load,
such as a water heater, shall be permitted to be locked or
sealed where located so as to be accessible.

230.94 Relative Location of Overcurrent Device and
Other Service Equipment. The overcurrent device shall
protect all circuits and devices.

Exception No. 1 : The service switch shall be permitted on
the supply side.

Exception No. 2: High-impedance shunt circuits, surge
arresters] Jypel^surge-protecUve devices, surge-protective
capacitors, and instrument transformers (current and
voltage) shall be permitted to be connected and installed
on the supply side of the service disconnecting means as
permitted by 230,82.

Exception No. 3: Circuits for load management devices
shall be permitted to be connected on the supply side of the
service overcurrent device where separately provided with
overcurrent protection.

Exception No. 4: Circuits used only for the operation of
fire alarm, other protective signaling systems, or the supply
to fire pump equipment shall be permitted to be connected
on the supply side of the service overcurrent device where
separately provided with overcurrent protection.

Exception No. 5: Meters nominally rated not in excess of
600 volts shall be permitted, provided all metal housings
and service enclosures are grounded.

Exception No. 6: Where service equipment is power
operable, the control circuit shall be permitted to be
connected ahead of the service equipment if suitable
overcurrent protection and disconnecting means are
provided.

230.95 Ground-Fault Protection of Equipment.

Ground-fault protection of equipment shall be provided for
solidly grounded wye electric services of more than 150
volts to ground but not exceeding 600 volts phase-to-phase
for each service disconnect rated 1000 amperes or more.
The grounded conductor for the solidly grounded wye
system shall be connected directly to ground througJ^Cta^
'j^oundSg eiectrod^^ system, a^ specifietfin 250 JOJ without
inserting any resistor or impedance device.

The rating of the service disconnect shall be
considered to be the rating of the largest fuse that can be
installed or the highest continuous current trip setting for
which the actual overcurrent device installed in a circuit
breaker is rated or can be adjusted.

Exception: The ground-fault protection provisions of this
section shall not apply to a service disconnect for a
continuous industrial process where a nonorderly
shutdown will introduce additional or increased hazards.

(A) Setting. The ground-fault protection system shall
operate to cause the service disconnect to open all
ungrounded conductors of the faulted circuit. The
maximum setting of the ground-fault protection shall be
1200 amperes, and the maximum time delay shall be one
second for ground-fault currents equal to or greater than
3000 amperes.

(B) Fuses. If a switch and fuse combination is used, the
fuses employed shall be capable of interrupting any current
higher than the interrupting capacity of the switch during a
time that the ground-fault protective system will not cause
the switch to open.

(C) Performance Testing. The ground-fault protection
system shall be performance tested when first installed on
site. The test shall be conducted in accordance with
instructions that shall be provided with the equipment. A
written record of this test shall be made and shall be
available to the authority having jurisdiction.

FPN No. 1 : Ground-fauh protection that functions to open
the service disconnect affords no protection from faults on
the line side of the protective element. It serves only to limit
damage to conductors and equipment on the load side in the
event of an arcing ground fault on the load side of the
protective element.

FPN No. 2: This added protective equipment at the service
equipment may make it necessary to review the overall
wiring system for proper selective overcurrent protection
coordination. Additional installations of ground-fault
protective equipment may be needed on feeders and branch
circuits where maximum continuity of electric service is
necessary.

FPN No. 3: Where ground- fault protection is provided for
the service disconnect and interconnection is made with
another supply system by a transfer device, means or
devices may be needed to ensure proper ground-fault
sensing by the ground-fault protection equipment.

FPN No. 4: See 517.17(A) for information on where an
additional step of ground-fault protection is required for
hospitals and other buildings with critical areas or life
support equipment.

VIII. Services Exceeding 600 Volts, Nominal

230.200 General. Service conductors and equipment used
on circuits exceeding 600 volts, nominal, shall comply with
all the applicable provisions of the preceding sections of

2010 California Electrical Code

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230.202

ARTICLE 230 - SERVICES

this article and with the following sections that supplement
or modify the preceding sections. In no case shall the
provisions of Part VIII apply to equipment on the supply
side of the service point.

FPN: For clearances of conductors of over 600 volts,
nominal, see ANSI C2-2007, National Electrical Safety
Code.

230.202 Service-Entrance Conductors. Service-entrance
conductors to buildings or enclosures shall be installed to
conform to 230.202(A) and (B).

(A) Conductor Size. Service-entrance conductors shall not
be smaller than 6 AWG unless in multiconductor cable.
Multiconductor cable shall not be smaller than 8 AWG.
(B) Wiring Methods. Service-entrance conductors shall
be installed by one of the wiring methods covered in
300.37 and 300.50.

230.204 Isolating Switches.

(A) Where Required. Where oil switches or air, oil,
vacuum, or sulfur hexafluoride circuit breakers constitute
the service disconnecting means, an isolating switch with
visible break contacts shall be installed on the supply side
of the disconnecting means and all associated service
equipment.

Exception: An isolating switch shall not be required where
the circuit breaker or switch is mounted on removable
truck panels or metal-enclosed switchgear units where both
of the following conditions apply:

(1) Cannot be opened unless the circuit is disconnected.

(2) Where all energized parts are automatically
disconnected when the circuit breaker or switch is removed
from the normal operating position.

(B) Fuses as Isolating Switch. Where fuses are of the type
that can be operated as a disconnecting switch, a set of such
fuses shall be permitted as the isolating switch.

(D) Connection to Ground, Isolating switches shall be
provided with a nieans for readily connecting the load side
conductors to a grounding electrode system, equipmenj
^ound busbar, ; or grounded steel structure when
disconnected from the source of supply.

A means for grounding the load side conductors to a
gro^mdittg electrode system^ eqgipmeiit groutiditig busbatj^
ot^ow^^ shall not be required for any

duplicate isolating switch installed and maintained by the
electric supply company.

230.205 Disconnecting Means.

(A) Location. The service disconnecting means shall be
located in accordance with 230.70.

For eitiijet ; ;6vei&ad or undetgnyutid primar>|
Bftliibutioii : s)^stem$;: on private ■ property, the seryicd
(dftcomect : shk^ii :l>^ ■ i^miitted to be JcMcated^^^^^^ a loc^m
|hM is |K>t ^^^'^}iyi^^^^]^\^i

(B) Type. Each service disconnect shall simultaneously
disconnect all ungrounded service conductors that it
controls and shall have a fault-closing rating that is not less
than the maximum short-circuit current available at its
supply terminals.

Where fused switches or separately mounted fuses are
installed, the fuse characteristics shall be permitted to
contribute to the fault-closing rating of the disconnecting
means.

(C) Remote Control. For multibuilding, industrial
installations under single management, the service
disconnecting means shall be permitted to be located at a
separate building or structure. In such cases, the service
disconnecting means shall be permitted to be electrically
operated by a readily accessible, remote-control device.
230.206 Overcurrent Devices as Disconnecting Means.
Where the circuit breaker or alternative for it, as specified
in 230.208 for service overcurrent devices, meets the
requirements specified in 230.205, they shall constitute the
service disconnecting means.

230.208 Protection Requirements. A short-circuit
protective device shall be provided on the load side of, or
as an integral part of, the service disconnect, and shall
protect all ungrounded conductors that it suppHes. The
protective device shall be capable of detecting and
interrupting all values of current, in excess of its trip setting
or melting point, that can occur at its location. A fuse rated
in continuous amperes not to exceed three times the
ampacity of the conductor, or a circuit breaker with a trip
setting of not more than six times the ampacity of the
conductors, shall be considered as providing the required
short-circuit protection.

FPN: See Table 310.67 through Table 310.86 for
ampacities of conductors rated 2001 volts and above.
Overcurrent devices shall conform to 230.208(A) and (B).

(A) Equipment Type. Equipment used to protect service-
entrance conductors shall meet the requirements of Article
490, Part II.

(B) Enclosed Overcurrent Devices. The restriction to 80
percent of the rating for an enclosed overcurrent device for
continuous loads shall not apply to overcurrent devices
installed in systems operating at over 600 volts.

230.209 Surge Arresters (Lightning Arresters).

Surge arresters installed in accordance with the
requirements of Article 280 shall be permitted on each
ungrounded overhead service conductor.

230.210 Service Equipment — General Provisions.
Service equipment, including instrument transformers,
shall conform to Article 490, Part I.

230.211 Metal-Enclosed Switchgear. Metal-enclosed
switchgear shall consist of a substantial metal structure and
a sheet metal enclosure. Where installed over a
combustible floor, suitable protection thereto shall be
provided.

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ARTICLE 240 - OVERCURRENT PROTECTION

240.4

230.212 Over 35,000 Volts. Where the voltage exceeds
35,000 volts between conductors that enter a building, they
shall terminate in a metal-enclosed switchgear
compartment or a vault conforming to the requirements of
450.41 through 450.48.

ARTICLE 240

Overcttrrent Protection

I. General

240.1 Scope. Parts I through VII of this article provide
the general requirements for overcurrent protection and
overcurrent protective devices not more than 600 volts,
nominal. Part VIII covers overcurrent protection for those
portions of supervised industrial installations operating at
voltages of not more than 600 volts, nominal. Part IX
covers overcurrent protection over 600 volts, nominal.

FPN: Overcurrent protection for conductors and
equipment is provided to open the circuit if the current
reaches a value that will cause an excessive or dangerous
temperature in conductors or conductor insulation. See
also 110.9 for requirements for interrupting ratings and
110.10 for requirements for protection against fault
currents.

240.2 Definitions.

Current-Limiting Overcurrent Protective Device. A

device that, when interrupting currents in its current-
limiting range, reduces the current flowing in the faulted
circuit to a magnitude substantially less than that
obtainable in the same circuit if the device were replaced
with a solid conductor having comparable impedance.

Supervised Industrial Installation. For the purposes of
Part VIII, the industrial portions of a facility where all of
the following conditions are met:

(1) Conditions of maintenance and engineering supervision

ensure that only qualified persons monitor and service the
system.

(2) The premises wiring system has 2500 kVA or greater of
load used in industrial process(es), manufacturing
activities, or both, as calculated in accordance with
Article 220.

(3) The premises has at least one service or feeder that is
more than 150 volts to ground and more than 300 volts
phase-to-phase.

This definition excludes installations in buildings
used by the industrial facility for offices, warehouses,
garages, machine shops, and recreational facilities that are
not an integral part of the industrial plant, substation, or
control center.

Tap Conductors. As used in this article, a tap
conductor is defined as a conductor, other than a
service conductor, that has overcurrent protection
ahead of its point of supply that exceeds the value
permitted for similar conductors that are protected as
described elsewhere in 240.4.

240.3 Other Articles. Equipment shall be protected
against overcurrent in accordance with the article in
this Code that covers the type of equipment specified
in Table 240.3.

240.4 Protection of Conductors. Conductors, other than
flexible cords, flexible cables, and fixture wires, shall be
protected against overcurrent in accordance with their
ampacities specified in 310.15, unless otherwise
permitted or required in 240.4(A) through (G).

(A) Power Loss Hazard. Conductor overload protection
shall not be required where the interruption of the circuit
would create a hazard, such as in a material-handling
magnet circuit or fire pump circuit. Short-circuit
protection shall be provided.

FPN: See NFPA 20-2007, Standard for the Installation of
Stationary Pumps for Fire Protection.

(B) Devices Rated 800 Amperes or Less. The next
higher standard overcurrent device rating (above the
ampacity of the conductors being protected) shall be
permitted to be used, provided all of the following
conditions are met:

(1) The conductors being protected are not part of a
multioutlet branch circuit supplying receptacles for
cord-and-p lug-connected portable loads.

(2) The ampacity of the conductors does not correspond
with the standard ampere rating of a fuse or a circuit
breaker without overload trip adjustments above its
rating (but that shall be permitted to have other trip or
rating adjustments).

(3) The next higher standard rating selected does not
exceed 800 amperes.

2010 California Electrical Code

70-83

240.4

ARTICLE 240 - OVERCURRENT PROTECTION

Table 240.3 Other Articles

Equipment

Article

Air-conditioning and refrigerating

440

equipment

Appliances

422

Assembly occupancies

518

Audio signal processing, amplification,

640

and reproduction equipment

Branch circuits

210

Busways

368

Capacitors

460

Class 1, Class 2, and Class 3 remote-

725

control, signaling, and power-limited

circuits

Closed-loop and programmed power

780

distribution

Cranes and hoists

610

Electric signs and outhne lighting

600

Electric welders

630

Electrolytic cells

668

Elevators, dumbwaiters, escalators.

620

moving walks, wheelchair lifts, and

stairway chair lifts

Emergency systems

700

Fire alarm systems

760

Fire pumps

695

Fixed electric heating equipment for

427

pipelines and vessels

Fixed electric space-heating equipment

424

Fixed outdoor electric deicing and snow-

426

melting equipment

Generators

445

Health care facilities

517

Induction and dielectric heating equipment

665

Industrial machinery

670

Luminaires (lighting fixtures),

410

lampholders, and lamps

Motion picture and television studios and

530

similar locations

Motors, motor circuits, and controllers

430

Phase converters

455

Pipe organs

650

Receptacles

406

Services

230

Solar photovoltaic systems

690

Switchboards and panelboards

408

Theaters, audience areas of motion picture

520

and television studios, and similar

locations

Transformers and transformer vaults

450

X-ray equipment

660

overcurrent device is rated over 800 amperes, the ampacity

of the conductors it protects shall be equal to or greater
than the rating of the overcurrent device defined in 240.6.

(D) Small Conductors. Unless specifically permitted in
240.4(E) or (G), the overcurrent protection^hall not exceed
that required by (D)(1) through (D)(7) after aay correction
factors for ambient tjei33|)eratoe a§d nianber of conductors
have been appliedJ

(i) iSAWG Copilen 7 ampereSj provided all the

( 1 ) '^mtinuom}^^

(2) < Ovaciidrent l>ro^cifo|tis|ffOvid^^^ following:

a; BranchH^ircuit-latfed circuit breakers listed and

rnarkedforus|w^^ 1 8; AWG copper w^
b: feanch-circuit-rated fiises listed and marked for use

jiyith;18;AWG|p^^^^^
cl ^ Giass_ GC;,^^ Gjass|[,; or' ClassT fiised
p),7 '1.6' aWG; Goppln'TITamgires,,;^]^^ ^all the
foilowin^';cqttdi^^^

( 1 ) jCpntii^upUjs, Iba'ds, ||) not exceed i athperes.

(2) pverciiront piptec& of & following:

a. VBi^anchncirciiit-Jiatea , VckcMit bi;eakers listed 2 and

m^ked; for[us^ W'][th - l:$:;AW6icbpper wfe
b^;®ranch-citcmt-ISfe5^ listM^^and^inarked fcr'use

g^'jCSs^GglJiasil?^

0j i2^' AWG/Alumn^ .Qoiigei^Giad Ainmimm*^

15 amperes;

(6) iO AV^AJurBdi^^

25 amperes

(E) Tap Conductors. Tap conductors shall be permitted to be
protected against overcurrent in accordance with the following:

(1) 210.19(A)(3) and (A)(4), Household Ranges and
Cooking Appliances and Other Loads

(2) 240.5(B)(2), Fixture Wire

(3) 240.21, Location in Circuit

(4) 368.17(B), Reduction in Ampacity Size of Busway

(5) 368.17(C), Feeder or Branch Circuits (busway taps)

(6) 430.53(D), Single Motor Taps

(F) Transformer Secondary Conductors. Single-phase (other
than 2-wire) and multiphase (other than delta-delta, 3-wire)
transformer secondary conductors shall not be considered to be
protected by the primary overcurrent protective device.
Conductors supplied by the secondary side of a single-phase
transformer having a 2-wire (single-voltage) secondary, or a
three-phase, delta-delta connected transformer having a 3-wire
(single- voltage) secondary, shall be permitted to be protected by
overcurrent protection provided on the primary (supply) side of
the transformer, provided this protection is in accordance with
450.3 and does not exceed the value determined by multiplying

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2010 California Electrical Code

ARTICLE 240 - OVERCURRENT PROTECTION

240.6

the secondary conductor ampacity by the secondary-to-primary

transformer voltage ratio.

(G) Overcurrent Protection for Specific Conductor

Applications. Overcurrent protection for the specific

conductors shall be permitted to be provided as referenced

in Table 240.4(G).

Table 240.4(G) Specific Conductor Applications

Conductor

Article

Section

Air-conditioning and
refrigeration
equipment circuit
conductors

440, Parts III, VI

Capacitor circuit
conductors

460

460.8(B) and
460.25(A)-(D)

Control and

instrumentation
circuit conductors
(TypelTC)

727

727.9

Electric welder circuit
conductors

630

630.12 and 630.32

Fire alarm system circuit
conductors

760

760.23, 760.24,

760.41, and
Chapter 9, Tables
12(A) and 12(B)

Motor-operated
appliance circuit
conductors

422, Part II

Motor and motor-control
circuit conductors

430, Parts III, IV,
V, VI, VII

Phase converter supply
conductors

455

455.7

Remote-control,

signaling, and power-
limited circuit
conductors

725

725.23, 725.24,

725.41, and
Chapter 9, Tables
11(A) and 11(B)

Secondary tie conductors

450

450.6

240.5 Protection of Flexible Cords, Flexible Cables, and
Fixture Wires. Flexible cord and flexible cable, including
tinsel cord and extension cords, and fixture wires shall be
protected against overcurrent by either 240.5(A) or (B).

(A) Ampacities. Flexible cord and flexible cable shall be
protected by an overcurrent device in accordance with their
ampacity as specified in Table 400.5(A) and Table
400.5(B). Fixture wire shall be protected against
overcurrent in accordance with its ampacity as specified in
Table 402.5. Supplementary overcurrent protection, as
covered in 240.10, shall be permitted to be an acceptable
means for providing this protection.

(B) Branch-Circuit Overcurrent Device. Flexible cord
shall be protected, where supplied by a branch circuit, in
accordance with one of the methods described in

240.5(B)(1), (B)(3), or (B)(4). RxtiJ^: w^

jsrQtected, where supplied by a branch ciri^uit, in
bi:cord4icewithi240^^^

(1) Supply Cord of Listed Appliance or Ltimiiiaire.;

Where flexible cord or tinsel cord is approved for and used
with a specific listed appliance or luminaire^^ it shall be
considered to be protected when applied within the
appliance or liiminaire listing requirements. For the
jpurposes of this section, a iuminaire may be either portable
orpemianent;

(2) Fixture Wire. Fixture wire shall be permitted to be
tapped to the branch-circuit conductor of a branch circuit in
accordance with the following:

(1) 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of
run length

(2) 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of
run length

(3) 20-ampere circuits — 14 AWG and larger

(4) 30-ampere circuits — 14 AWG and larger

(5) 40-ampere circuits — 12 AWG and larger

(6) 50-ampere circuits — 12 AWG and larger

(3) Extension Cord Sets. Flexible cord used in listed
extension cord sets shall be considered to be protected
when applied within the extension cord listing
requirements.

(4) Field Assembled Extension Cord Sets. Flexible cord
used in extension cords made with separately listed and
installed components shall be permitted to be suppHed by a
branch circuit in accordance with the following:

20-ampere circuits — 16 AWG and larger

240.6 Standard Ampere Ratings.

(A) Fuses and Fixed-Trip Circuit Breakers. The

standard ampere ratings for fuses and inverse time circuit
breakers shall be considered 15, 20, 25, 30, 35, 40, 45, 50,
60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300,
350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000,
2500, 3000, 4000, 5000, and 6000 amperes. Additional
standard ampere ratings for fuses shall be I, 3, 6, 10, and
601. The use of fuses and inverse time circuit breakers with
nonstandard ampere ratings shall be permitted.

(B) Adjustable-Trip Circuit Breakers. The rating of
adjustable-trip circuit breakers having external means for
adjusting the current setting (long-time pickup setting), not
meeting the requirements of 240.6(C), shall be the
maximum setting possible.

(C) Restricted Access Adjustable-Trip Circuit
Breakers. A circuit breaker(s) that has restricted access to
the adjusting means shall be permitted to have an ampere
rating(s) that is equal to the adjusted current setting (long-
time pickup setting). Restricted access shall be defined as
located behind one of the following:

20 1 California Electrical Code

70-85

240.8

ARTICLE 240 - OVERCURRENT PROTECTION

(1) Removable and scalable covers over the adjusting means

(2) Bolted equipment enclosure doors

(3) Locked doors accessible only to qualified personnel

240.8 Fuses or Circuit Breakers in Parallel. Fuses and
circuit breakers shall be permitted to be connected in parallel
where they are factory assembled in parallel and listed as a
unit. Individual fuses, circuit breakers, or combinations
thereof shall not otherwise be connected in parallel.

240.9 Thermal Devices. Thermal relays and other devices
not designed to open short circuits or ground faults shall
not be used for the protection of conductors against
overcurrent due to short circuits or ground faults, but the
use of such devices shall be permitted to protect motor
branch-circuit conductors from overload if protected in
accordance with 430.40.

240.10 Supplementary Overcurrent Protection. Where
supplementary overcurrent protection is used for
luminaires, appliances, and other equipment or for internal
circuits and components of equipment, it shall not be used
as a substitute for required branch-circuit overcurrent
devices or in place of the required branch-circuit
protection. Supplementary overcurrent devices shall not be
required to be readily accessible.

240.12 Electrical System Coordination.

Where an orderly shutdown is required to minimize the
hazard(s) to personnel and equipment, a system of
coordination based on the following two conditions shall
be permitted:

(1) Coordinated short-circuit protection

(2) Overload indication based on monitoring systems or
devices

FPN: The monitoring system may cause the condition
to go to alarm, allowing corrective action or an orderly
shutdown, thereby minimizing personnel hazard and
equipment damage.

240.13 Ground-Fault Protection of Equipment.

Ground-fault protection of equipment shall be provided in
accordance with the provisions of 230.95 for soHdly
grounded wye electrical systems of more than 150 volts to
ground but not exceeding 600 volts phase-to-phase for each
individual device used as a building or structure main
disconnecting means rated 1000 amperes or more.

The provisions of this section shall not apply to the
disconnecting means for the following:

(1) Continuous industrial processes where a nonorderly
shutdown will introduce additional or increased
hazards

(2) Installations where ground- fault protection is provided
by other requirements for services or feeders

(3) Fire pumps

240jl§ Ungrounded Conductors.

(A) Overcurrent Device Required. A fuse or an
overcurrent trip unit of a circuit breaker shall be connected
in series with each ungrounded conductor. A combination
of a current transformer and overcurrent relay shall be
considered equivalent to an overcurrent trip unit.

FPN: For motor circuits, see Parts III, IV, V, and XI of
Article 430.

(B) Circuit Breaker as Overcurrent Device. Circuit
breakers shall open all ungrounded conductors of the
circuit both manually and automatically unless otherwise
permitted in |4pVl^(B)(l), (B)(2), and (B)(3).

(1) Multiwire Branch Circuit. Except where limited by
210.4(B), individual single-pole circuit breakers, with or
without identified handle ties, shall be permitted as the
protection for each ungrounded conductor of multiwire
branch circuits that serve only single-phase line-to -neutral
loads.

(2) Grounded Single-Phase and 3-Wire dc Circuits. In

grounded systems, individual single-pole circuit breakers
with identified handle ties shall be permitted as the
protection for each ungrounded conductor for line-to-line
connected loads for single-phase circuits or 3 -wire, direct-
current circuits.

(3) 3-Phase and 2-Phase Systems. For line-to-line loads
in 4-wire, 3-phase systems or 5-wire, 2-phase systems
having a grounded neutral |0Mt and no conductor
operating at a voltage greater than permitted in 210.6,
individual single-pole circuit breakers with identified
handle ties shall be permitted as the protection for each
ungrounded conductor.

(C) Closed-Loop Power Distribution Systems. Listed
devices that provide equivalent overcurrent protection in
closed-loop power distribution systems shall be permitted
as a substitute for fuses or circuit breakers.

240.21 Location in Circuit. Overcurrent protection shall be
provided in each ungrotmded circuit conductor and shall be
located at the point where the conductors receive their supply
except as specified in 240.21(A) through (H). CoBdWctSri
supplied under the provisions of 240.21(A) through (H) shall
no^ supply another conductor except through an overcurrent
protective device meeting the requu-ements of 240.4.
(A) Branch-Circuit Conductors. Branch-circuit tap
conductors meeting the requirements specified in 210.19
shall be permitted to have overcurrent protection as
specified in M&JZOl

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2010 California Electrical Code

ARTICLE 240 - OVERCURRENT PROTECTION

240.21

(B) Feeder Taps. Conductors shall be permitted to be
tapped, without overcurrent protection at the tap, to a feeder
as specified in 240.21(B)(1) through (B)(5). The provisions
of 240.4(B) shall not be permitted for tap conductors.

(1) Taps Not over 3 m (10 ft) Long. Where the length of
the tap conductors does not exceed 3 m (10 ft) and the tap
conductors comply with all of the following:

(1) The ampacity of the tap conductors is

a. Not less than the combined calculated loads on the

circuits supplied by the tap conductors, and

b. Not less than the rating of the device supplied by

the tap conductors or not less than the rating of the
overcurrent protective device at the termination of
the tap conductors.

(2) The tap conductors do not extend beyond the
switchboard, panelboard, disconnecting means, or
control devices they supply.

(3) Except at the point of connection to the feeder, the tap
conductors are enclosed in a raceway, which shall
extend from the tap to the enclosure of an enclosed
switchboard, panelboard, or control devices, or to the
back of an open switchboard.

(4) For field installations where the tap conductors leave
the enclosure or vault in which the tap is made, the
rating of the overcurrent device on the line side of the
tap conductors shall not exceed 10 times the ampacity
of the tap conductor.

FPN: For overcurrent protection requirements for
panelboards, see ffp836J

(2) Taps Not over 7.5 m (25 ft) Long. Where the length
of the tap conductors does not exceed 7.5 m (25 ft) and the
tap conductors comply with all the following:

(1) The ampacity of the tap conductors is not less than
one-third of the rating of the overcurrent device
protecting the feeder conductors.

(2) The tap conductors terminate in a single circuit breaker
or a single set of fuses that Hmit the load to the
ampacity of the tap conductors. This device shall be
permitted to supply any number of additional
overcurrent devices on its load side.

(3) The tap conductors are protected from physical damage
by being enclosed in an approved raceway or by other
approved means.

(3) Taps Supplying a Transformer [Primary Plus
Secondary Not over 7.5 m (25 ft) Long]. Where the tap
conductors supply a transformer and comply with all the
following conditions:

(1) The conductors supplying the primary of a transformer
have an ampacity at least one-third the rating of the
overcurrent device protecting the feeder conductors.

(2) The conductors supplied by the secondary of the

transformer shall have an ampacity that is not less than
the value of the primary-to-secondary voltage ratio
multiplied by one-third of the rating of the overcurrent
device protecting the feeder conductors.

(3) The total length of one primary plus one secondary
conductor, excluding any portion of the primary conductor
that is protected at its ampacity, is not over 7.5 m (25 ft).

(4) The primary and secondary conductors are protected
from physical damage by being enclosed in an
approved raceway or by other approved means.

(5) The secondary conductors terminate in a single circuit
breaker or set of fuses that limit the load current to not
more than the conductor ampacity that is permitted by
310.15.

(4) Taps over 7.5 m (25 ft) Long. Where the feeder is in a high
bay manufacturing building over 1 1 m (35 ft) high at walls and
the installation complies with all the following conditions:

(1) Conditions of maintenance and supervision ensure that
only qualified persons service the systems.

(2) The tap conductors are not over 7.5 m (25 ft) long
horizontally and not over 30 m (100 ft) total length.

(3) The ampacity of the tap conductors is not less than
one-third the rating of the overcurrent device
protecting the feeder conductors.

(4) The tap conductors terminate at a single circuit breaker
or a single set of fiises that limit the load to the
ampacity of the tap conductors. This single overcurrent
device shall be permitted to supply any number of
additional overcurrent devices on its load side.

(5) The tap conductors are protected from physical damage
by being enclosed in an approved raceway or by other
approved means,

(6) The tap conductors are continuous from end-to-end and
contain no sphces.

(7) The tap conductors are sized 6 AWG copper or 4 AWG
aluminum or larger.

(8) The tap conductors do not penetrate walls, floors, or
ceilings.

(9) The tap is made no less than 9 m (30 ft) from the floor.

(5) Outside Taps of Unlimited Length. Where the
conductors are located outdoors of a building or structure,
except at the point of load termination, and comply with all
of the following conditions:

( 1 ) The conductors are protected from physical damage in
an approved manner.

(2) The conductors terminate at a single circuit breaker or
a single set of ftises that limit the load to the ampacity
of the conductors. This single overcurrent device shall
be permitted to supply any number of additional
overcurrent devices on its load side.

2010 California Electrical Code

70-87

240.21

ARTICLE 240 - OVERCURRENT PROTECTION

(3) The overcurrent device for the conductors is an integral
part of a disconnecting means or shall be located
immediately adjacent thereto.

(4) The disconnecting means for the conductors is installed
at a readily accessible location complying with one of
the following:

a. Outside of a building or structure

b. Inside, nearest the point of entrance of the

conductors

c. Where installed in accordance with 230.6, nearest

the point of entrance of the conductors

(C) Transformer Secondary Conductors. A s^t of
Conductors feeding a singie lo^d; or each set of conductors
feeding separate loads, shall be permitted to be connected
to a transformer secondary, without overcurrent protection
at the secondary, as specified in 240.21(C)(1) through
(C)(6). The provisions of 240.4(B) shall not be permitted
for transformer secondary conductors.

FPN: For overcurrent protection requirements for
transformers, see 450.3.

(1) Protection by Primary Overcurrent Device.

Conductors supplied by the secondary side of a single-
phase transformer having a 2 -wire (single- voltage)
secondary, or a three-phase, delta-delta coimected
transformer having a 3-wire (single-voltage) secondary,
shall be permitted to be protected by overcurrent protection
provided on the primary (supply) side of the transformer,
provided this protection is in accordance with 450.3 and
does not exceed the value determined by multiplying the
secondary conductor ampacity by the secondary-to-primary
transformer voltage ratio.

Single-phase (other than 2-wire) and multiphase (other
than delta-delta, 3-wire) transformer secondary conductors
are not considered to be protected by the primary
overcurrent protective device.

(2) Transformer Secondary Conductors Not over 3 m
(10 ft) Long. Where the length of secondary conductor
does not exceed 3 m (10 ft) and complies with all of the
following:

(1) The ampacity of the secondary conductors is

a. Not less than the combined calculated loads on the

circuits supplied by the secondary conductors, and

b. Not less than the rating of the device supplied by

the secondary conductors or not less than the
rating of the overcurrent-protective device at the
termination of the secondary conductors

(2) The secondary conductors do not extend beyond the
switchboard, panelboard, disconnecting means, or
control devices they supply.

(3) The secondary conductors are enclosed in a raceway,
which shall extend from the transformer to the
enclosure of an enclosed switchboard, panelboard, or
control devices or to the back of an open switchboard.

(4) For field; installatidpswl^^^ th^ secondary conductors
lea;ve-;/tlie enclospf e or yatilt in which: the supply
b|Di^ecti^Qh;/ is;^:^m^ ;J;he; ^rating of the overcurrent

dpvi66: ■protecting
nit^tiiplied By -t^

|&it^ge5jtaii|>^,^iii4l;

tiije^,:{)|nrnary of the transformer,
prirnai^:' to; sec^ transformer

i6t exqeefljpjim the ampacity of

FPN: For overcurrent protection requirements for
panelboards, see |083,|>

(3) Industrial Installation Secondary Conductors Not
over 7.5 m (25 ft) Long. For industrial installations only,
where the length of the secondary conductors does not
exceed 7.5 m (25 ft) and compHes with all of the following:

(1) Conditions of mairif^nance and supervisioE ensure that
only qualified pers|ns service the systems j

(2) The ampacity of the secondary conductors is not less
than the secondary current rating of the transformer, and
the sum of the ratings of the overcurrent devices does
not exceed the ampacity of the secondary conductors.

(3) All overcurrent devices are grouped.

(4) The secondary conductors are protected from physical
damage by being enclosed in an approved raceway or
by other approved means.

(4) Outside Secondary Conductors. Where the
conductors are located outdoors of a building or structure,
except at the point of load termination, and comply with all
of the following conditions:

(1) The conductors are protected from physical damage in
an approved manner.

(2) The conductors terminate at a single circuit breaker or
a single set of frises that limit the load to the ampacity
of the conductors. This single overcurrent device shall
be permitted to supply any number of additional
overcurrent devices on its load side.

(3) The overcurrent device for the conductors is an integral
part of a disconnecting means or shall be located
immediately adjacent thereto.

(4) The disconnecting means for the conductors is installed
at a readily accessible location complying with one of
the following:

a. Outside of a building or structure

b. Inside, nearest the point of entrance of the
conductors

c. Where installed in accordance with 230.6, nearest

the point of entrance of the conductors

(5) Secondary Conductors from a Feeder Tapped
Transformer. Transformer secondary conductors installed
in accordance with 240.21(B)(3) shall be permitted to have
overcurrent protection as specified in that section.

(6) Secondary Conductors Not over 7.5 m (25 ft) Long.

Where the length of secondary conductor does not exceed
7.5 m (25 ft) and complies with all of the following:

70-88

2010 California Electrical Code

ARTICLE 240 - OVERCURRENT PROTECTION

240.24

(1) The secondary conductors shall have an ampacity that is not

less than the value of the primary-to-secondary voltage
ratio multiplied by one-third of the rating of the overcurrent
device protecting the primary of the transformer.

(2) The secondary conductors terminate in a single circuit
breaker or set of fuses that limit the load current to not
more than the conductor ampacity that is permitted by
310.15.

(3) The secondary conductors are protected from physical
damage by being enclosed in an approved raceway or
by other approved means.

(D) Service Conductors. Service conductors shall be
permitted to be protected by overcurrent devices in
accordance with 230.91.

(E) Busway Taps. Busways and busway taps shall be
permitted to be protected against overcurrent in accordance

with 368.17.

(F) Motor Circuit Taps. Motor-feeder and branch-circuit
conductors shall be permitted to be protected against
overcurrent in accordance with 430.28 and 430.53,
respectively.

(G) Conductors from Generator Terminals. Conductors
from generator terminals that meet the size requirement in
445.13 shall be permitted to be protected against overload by
the generator overload protective device(s) required by 445. 12.

(H) Battery Conductors^ pVerciiiTerifproteQtipn shall be

permiited[ to be ijaslalied as c}ose_a|^practicabie jo_ the
stomgc^^ttpty-^ tettt)^als_^m^ a___J[0^^
imt^^4^_iof ^ the ^^y^rcmrpnt ^jotectjoii wiffi|a^^:: j
hazardoiJjb^ be peri^edl

240.22 Grounded Conductor. No overcurrent device
shall be connected in series with any conductor that is
intentionally grounded, unless one of the following two
conditions is met:

(1) The overcurrent device opens all conductors of the
circuit, including the grounded conductor, and is
designed so that no pole can operate independently.

(2) Where required by 430.36 or 430.37 for motor
overload protection.

240.23 Change in Size of Grounded Conductor. Where
a change occurs in the size of the ungrounded conductor, a
similar change shall be permitted to be made in the size of
the grounded conductor.

240.24 Location in or on Premises.

(A) Accessibility. Overcurrent devices shall be readily
accessible and shall be installed so that the center of the grip of
the operating handle of the switch or circuit breaker, when in its
highest position, is not more than 2.0 m (6 ft 7 in.) above the
floor or working platform, unless one of the following applies:

(1) For busways, as provided in 368.17(C).

(2) For supplementary overcurrent protection, as described in
240.10.

(3) For overcurrent devices, as described in 225.40 and 230.92.

(4) For overcurrent devices adjacent to utilization equipment
that they supply, access shall be permitted to be by portable
means.

(B) Occupancy. Each occupant shall have ready access to all
overcurrent devices protecting the conductors supplying that
occupancy, unless oSerwise permiged in 246.2|(B5(1} and

(if) Service aiid Feeder Overcuireiit Devices* Where electric
service and electrical maintenance are provided by the building
management and where these are under continuous building
management supervision, the service overcurrent devices and
feeder overcurrent devices supplying more than one occupancy
shall be permitted to be accessible only to authorized
management personnel in the following:

(1) Multiple-occupancy buildmgs

(2) Guest rooms or guest suites

(2)'^^Branch*C^cirft Ove^^ Where electric

service and electrical maintenance are provided by the building
management and where these are under continuous building
management supervision, the branch-circuit overcurrent devices
supplying any guest rooms or guest suites withQUt penBikiedt
ptpvisions for cookkig shall be permitted to be accessible only
to authorized management personnel.

(C) Not Exposed to Physical Damage. Overcurrent devices
shall be located where they will not be exposed to physical
damage.

FPN: See 1 10.1 1, Deteriorating Agents.

(D) Not in Vicinity of Easily Ignitible Material. Overcurrent
devices shall not be located in the vicinity of easily ignitible
material, such as in clothes closets.

(E) Not Located in Bathrooms. In dwelling units and guest
rooms or guest suites of hotels and motels, overcurrent devices,
other than supplementary overcurrent protection, shall not be
located in bathrooms.

(E) Not Located <^^^^ Steps. Oye|cuiteiit <fevices shajl oot be
legated over stepsj>f a staii;wayl

2010 California Electrical Code

70-89

240.30

ARTICLE 240 - OVERCURRENT PROTECTION

III. Enclosures
240.30 General.

(A) Protection from Physical Damage. Overcurrent
devices shall be protected from physical damage by one of
the following:

(1) Installation in enclosures, cabinets, cutout boxes, or
equipment assembhes

(2) Mounting on open-type switchboards, panelboards, or
control boards that are in rooms or enclosures free
from dampness and easily ignitible material and are
accessible only to qualified personnel

(B) Operating Handle. The operating handle of a circuit
breaker shall be permitted to be accessible without opening
a door or cover.

240.32 Damp or Wet Locations. Enclosures for overcurrent
devices in damp or wet locations shall comply with 312.2.

240.33 Vertical Position. Enclosures for overcurrent
devices shall be mounted in a vertical position unless that is
shown to be impracticable. Circuit breaker enclosures shall
be permitted to be installed horizontally where the circuit
breaker is installed in accordance with 240.81. Listed
busway plug-in units shall be permitted to be mounted in
orientations corresponding to the busway mounting position.

IV. Disconnecting and Guarding

240.40 Disconnecting Means for Fuses. Cartridge fuses
in circuits of any voltage where accessible to other than
quahfied persons, and all fuses in circuits over 150 volts to
ground, shall be provided with a disconnecting means on
their supply side so that each circuit containing fuses can
be independently disconnected from the source of power. A
cxirrent-limiting device without a disconnecting means shall
be permitted on the supply side of the service
disconnecting means as permitted by 230.82. A single
disconnecting means shall be permitted on the supply side
of more than one set of fiises as permitted by 430.112,
Exception, for group operation of motors and 424.22(C) for
fixed electric space-heating equipment.

240.41 Arcing or Suddenly Moving Parts. Arcing or
suddenly moving parts shall comply with 240.41(A) and (B).

(A) Location. Fuses and circuit breakers shall be located or
shielded so that persons will not be burned or otherwise
injured by their operation.

(B) Suddenly Moving Parts. Handles or levers of circuit
breakers, and similar parts that may move suddenly in such
a way that persons in the vicinity are Hkely to be injured by
being struck by them, shall be guarded or isolated.

V. Plug Fuses, Fuseholders, and Adapters

240.50 General.

(A) Maximum Voltage. Plug fuses shall be permitted to be
used in the following circuits:

(1) Circuits not exceeding 125 voUs between conductors

(2) Circuits supplied by a system having a grounded neutral
point where the line-to-neutral voltage does not exceed
150 volts

(B) Marking. Each fuse, fuseholder, and adapter shall be
marked with its ampere rating.

(C) Hexagonal Configuration. Plug fuses of 15 -ampere
and lower rating shall be identified by a hexagonal
configuration of the window, cap, or other prominent part
to distinguish them from fuses of higher ampere ratings.

(D) No Energized Parts. Plug fuses, fuseholders, and
adapters shall have no exposed energized parts after fuses
or fuses and adapters have been installed.

(E) Screw Shell. The screw shell of a plug-type fuseholder
shall be connected to the load side of the circuit.

240.51 Edison-Base Fuses.

(A) Classification. Plug fuses of the Edison-base type shall be
classified at not over 125 volts and 30 amperes and below.

(B) Replacement Only. Plug fuses of the Edison-base type
shall be used only for replacements in existing installations
where there is no evidence of overfusing or tampering.

240.52 Edison-Base Fuseholders. Fuseholders of the
Edison-base type shall be installed only where they are
made to accept Type S fuses by the use of adapters.

240.53 Type S Fuses. Type S fuses shall be of the plug
type and shall comply with 240.53(A) and (B).

(A) Classification. Type S fuses shall be classified at not
over 125 volts and to 15 amperes, 16 to 20 amperes, and
21 to 30 amperes.

(B) Noninterchangeable. Type S fuses of an ampere
classification as specified in 240.53(A) shall not be
interchangeable with a lower ampere classification. They
shall be designed so that they cannot be used in any
fuseholder other than a Type S fuseholder or a fuseholder
with a Type S adapter inserted.

240.54 Type S Fuses, Adapters, and Fuseholders.

(A) To Fit Edison-Base Fuseholders. Type S adapters
shall fit Edison-base fuseholders.

(B) To Fit Type S Fuses Only. Type S fuseholders and
adapters shall be designed so that either the fuseholder
itself or the fuseholder with a Type S adapter inserted
cannot be used for any fuse other than a Type S fuse.

70-90

2010 California Electrical Code

ARTICLE 240 - OVERCURRENT PROTECTION

240.85

(D) Nontamperable. Type S fuses, fuseholders, and
adapters shall be designed so that tampering or shunting
(bridging) would be difficult.

(E) Interchangeability. Dimensions of Type S fuses,
fuseholders, and adapters shall be standardized to permit
interchangeabihty regardless of the manufacturer.

VI. Cartridge Fuses and Fuseholders

240.60 General.

(A) Maximum Voltage — 300-Volt Type. Cartridge fuses
and fuseholders of the 300-volt type shall be permitted to
be used in the following circuits:

(1) Circuits not exceeding 300 volts between conductors

(2) Single-phase line-to-neutral circuits supplied from a 3-
phase, 4-wire, solidly grounded neutral source where
the line- to-neutral voltage does not exceed 300 volts

(B) Noninterchangeable — 0-6000-Ampere Cartridge
Fuseholders. Fuseholders shall be designed so that it will
be difficult to put a fuse of any given class into a
fuseholder that is designed for a current lower, or voltage
higher, than that of the class to which the fuse belongs.
Fuseholders for current-limiting fuses shall not permit
insertion of fuses that are not current-Umiting.

(C) Marking. Fuses shall be plainly marked, either by
printing on the fuse barrel or by a label attached to the
barrel showing the following:

(1) Ampere rating

(2) Voltage rating

(3) Interrupting rating where other than 10,000 amperes

(4) Current limiting where applicable

(5) The name or trademark of the manufacturer

The interrupting rating shall not be required to be
marked on fuses used for supplementary protection.

(D) Renewable Fuses. Class H cartridge fuses of the
renewable type shall be permitted to be used only for
replacement in existing installations where there is no
evidence of overfusing or tampering.

240.61 Classification. Cartridge fuses and fuseholders
shall be classified according to voltage and amperage
ranges. Fuses rated 600 volts, nominal, or less shall be
permitted to be used for voltages at or below their ratings.

VII. Circuit Breakers

240.80 Method of Operation. Circuit breakers shall be
trip fi*ee and capable of being closed and opened by manual
operation. Their normal method of operation by other than
manual means, such as electrical or pneumatic, shall be
permitted if means for manual operation are also provided.

240.81 Indicating. Circuit breakers shall clearly indicate
whether they are in the open "off or closed "on" position.

Where circuit breaker handles are operated vertically
rather than rotationally or horizontally, the "up" position of
the handle shall be the "on" position.

240.82 Nontamperable. A circuit breaker shall be of such
design that any alteration of its trip point (calibration) or the
time required for its operation requires dismantling of the device
or breaking of a seal for other than intended adjustments.

240.83 Marking.

(A) Durable and Visible. Circuit breakers shall be marked
with their ampere rating in a manner that will be durable
and visible after installation. Such marking shall be
permitted to be made visible by removal of a trim or cover.

(B) Location. Circuit breakers rated at 100 amperes or less
and 600 volts or less shall have the ampere rating molded,
stamped, etched, or similarly marked into their handles or
escutcheon areas.

(C) Interrupting Rating. Every circuit breaker having an
interrupting rating other than 5000 amperes shall have its
interrupting rating shown on the circuit breaker. The
interrupting rating shall not be required to be marked on
circuit breakers used for supplementary protection.

(D) Used as Switches. Circuit breakers used as switches in
120-volt and 277-volt fluorescent lighting circuits shall be
listed and shall be marked SWD or HID. Circuit breakers
used as switches in high-intensity discharge lighting
circuits shall be listed and shall be marked as HID.

(E) Voltage Marking. Circuit breakers shall be marked with a
voltage rating not less than the nominal system voltage that is
indicative of their capability to interrupt fault currents between
phases or phase to ground.

240.85 Applications. A circuit breaker with a straight voltage
rating, such as 240V or 480V, shall be permitted to be applied in
a circuit in which the nominal voltage between any two
conductors does not exceed the circuit breaker *s voltage rating.
A two-pole circuit breaker shall not be used for protecting a 3-
phase, comer-grounded delta circuit unless the circuit breaker is
marked 10-30 to indicate such suitability.

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240.86

ARTICLE 240 - OVERCURRENT PROTECTION

A circuit breaker with a slash rating, such as 1 20/240 V or
480Y/277V, shall be permitted to be applied in a soHdly
grounded circuit where the nominal voltage of any conductor to
ground does not exceed the lower of the two values of the
circuit breaker's voltage rating and the nominal voltage between
any two conductors does not exceed the higher value of the
circuit breaker's voltage rating.

FPN: Proper application of molded case circuit breakers
on 3-phase systems, other than solidly grounded wye,
particularly on comer grounded delta systems, considers
the circuit breakers' individual pole-interrupting
capability.

240.86 Series Ratings. Where a circuit breaker is used on a
circuit having an available fault current higher than the marked
interrupting rating by being connected on the load side of an
acceptable overcurrent protective device having a higher rating,
the circuit breaker shall meet the requirements specified in (A)
or(B),and(C).

(A) Selected Under Engineering Supervision in Existing
Installations. The series rated combination devices shall be
selected by a licensed professional engineer engaged primarily
in the design or maintenance of electrical installations. The
selection shall be documented and stamped by the professional
engineer. This documentation shall be available to those
authorized to design, install, inspect, maintain, and operate the
system. This series combination rating, including identification
of the upstream device, shall be field marked on the end use
equipment.

For calculated M^lic?;tio|is,;l|ie engineer shall ensure fimi
the downstream circuit breaker($) th at ai'e pait pfjie series
combination remain passive during the interruption period of"
tiie line sidQ &% rg^^

(B) Tested Combinations. The combination of line-side
overcurrent device and load-side circuit breaker(s) is tested and
marked on the end use equipment, such as switchboards and
panelboards.

5cgml)jn|^on: systSfe

(1) Motors are connected on the load side of the higher-rated
overcurrent device and on the line side of the lower-rated
overcurrent device, and

(2) The sum of the motor full-load currents exceeds 1 percent
of the interrupting rating of the lower-rated circuit breaker.

VIII. Supervised Industrial Installations

240.90 General. Overcurrent protection in areas of
supervised industrial installations shall comply with all of
the other appHcable provisions of this article, except as
provided in Part VIII. The provisions of Part VIII shall be
permitted only to apply to those portions of the electrical
system in the supervised industrial installation used
exclusively for manufacturing or process control activities.

240.92 Location in Circuit. An overcurrent device shall
be connected in each ungrounded circuit conductor as
required in 240.92(A) through (E).

(A) Feeder and Branch-Circuit Conductors. Feeder and
branch-circuit conductors shall be protected at the point the
conductors receive their supply as permitted in 240.21 or as
otherwise permitted in 240.92(B), (C), (D), or (E).

g):lieaer

(C) Transformer Secondary Conductors of Separately
Derived Systems. Conductors shall be permitted to be
connected to a transformer secondary of a separately derived
system, without overcurrent protection at the connection, where
the conditions of 240.92(C)(1), (C)(2), and (C)(3) are met

(1) Short-Circuit and Ground-Fault Protection. The

conductors shall be protected from short-circuit and
ground-fault conditions by complying with one of the
following conditions:

(1) The length of the secondary conductors does not exceed 30
m (100 ft) and the transformer primary overcurrent device
has a rating or setting that does not exceed 150 percent of
the value determined by multipl5dng the secondary
conductor ampacity by the secondary-to-primary
transformer voltage ratio.

(2) The conductors are protected by a differential relay with a
trip setting equal to or less than the conductor ampacity.

FPN: A differential relay is connected to be sensitive only to
short-circuit or fault currents within the protected zone and is
normally set much lower than the conductor ampacity. The
differential relay is connected to trip protective devices that
de-energize the protected conductors if a short-circuit
condition occurs.

(3) The conductors shall be considered to be protected
if calculations, made under engineering
supervision, determine that the system overcurrent
devices will protect the conductors within
recognized time vs. current limits for all short-
circuit and ground-fault conditions

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ARTICLE 240 - OVERCURRENT PROTECTION

240,100

Table 240.92(B) Tap Conductor Short-Circuit Current Ratings.

Tap conductors are considered to be protected under short-circuit
conditions when their short-circuit temperature limit is not
exceeded. Conductor heating under short-circuit conditions is
determined by ( 1 ) or (2) :

(1) Short-Circuit Formula for Copper Conductors
{I2IA2)t = 0.0297 log,o [(7^2 + 2U)I{T^ + 234)]

(2) Short-Circuit Formula for Aluminum Conductors

(12/A2)t = 0.0125 logio [(^2 + 228)/(r, + 228)]

where:

/ = short-circuit current in amperes

A = conductor area in circular mils

t = time of short circuit in seconds (for times less than or equal to
10 seconds)

Ti = initial conductor temperature in degrees Celsius.

T2 = final conductor temperature in degrees Celsius.

Copper conductor with paper, rubber, varnished cloth insulation,
T2 = 200

Copper conductor with thermoplastic insulation, 72 = 150

Copper conductor with cross-linked polyethylene insulation, T2 ^
250

Copper conductor with ethylene propylene rubber insulation, T2 =
250

Aluminum conductor with paper, rubber, varnished cloth
insulation, T2 = 200

Aluminum conductor with thermoplastic insulation, T2- 150

Aluminum conductor with cross-linked polyethylene insulation,
T2 = 250

Aluminum conductor with ethylene propylene rubber insulation,
T2 = 250

(2) Overload Protection. The conductors shall be
protected against overload conditions by complying with
one of the follow^ing:

(1) The conductors terminate in a single overcurrent device that
will hmit the load to the conductor ampacity.

(2) The sum of the overcurrent devices at the conductor
termination limits the load to the conductor ampacity. The
overcurrent devices shall consist of not more than six
circuit breakers or sets of fuses, mounted in a single
enclosure, in a group of separate enclosures, or in or on a
switchboard. There shall be no more than six overcurrent
devices grouped in any one location.

(3) Overcurrent relaying is connected [with a current
transformer(s), if needed] to sense all of the secondary
conductor current and limit the load to the conductor

ampacity by opening upstream or downstream devices.

(4) Conductors shall be considered to be protected if
calculations, made under engineering supervision,
determine that the system overcurrent devices will
protect the conductors Irom overload conditions.

(3) Physical Protection. The secondary conductors are
protected fi"om physical damage by being enclosed in an
approved raceway or by other approved means.

(D) Outside Feeder Taps. Outside conductors shall be
permitted to be tapped to a feeder or to be connected at a
transformer secondary, without overcurrent protection at
the tap or connection, where all the following conditions
are met:

(1) The conductors are protected from physical damage in
an approved maimer.

(2) The sum of the overcurrent devices at the conductor
termination limits the load to the conductor ampacity.
The overcurrent devices shall consist of not more than
six circuit breakers or sets of fuses mounted in a single
enclosure, in a group of separate enclosures, or in or
on a switchboard. There shall be no more than six
overcurrent devices grouped in any one location.

(3) The tap conductors are installed outdoors of a building
or structure except at the point of load termination.

(4) The overcurrent device for the conductors is an integral
part of a disconnecting means or shall be located
immediately adjacent thereto.

(5) The disconnecting means for the conductors are
installed at a readily accessible location complying
with one of the following:

a. Outside of a building or structure

b. Inside, nearest the point of entrance of the

conductors

c. Where installed in accordance with 230.6, nearest

the point of entrance of the conductors

(E) Protection by Primary Overcurrent Device.

Conductors supplied by the secondary side of a transformer
shall be permitted to be protected by overcurrent protection
provided on the primary (supply) side of the transformer,
provided the primary device time-current protection
characteristic, multiplied by the maximum effective
primary-to-secondary transformer voltage ratio, effectively
protects the secondary conductors.

IX. Overcurrent Protection over 600 Volts, Nominal

240.100 Feeders and Branch Circuits.

(A) Location and Type of Protection. Feeder and branch-
circuit conductors shall have overcurrent protection in each

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240.101

ARTICLE 250 - GROUNDING AND BONDING

ungrounded conductor located at the point where the
conductor receives its supply or at an alternative location in
the circuit when designed under engineering supervision
that includes but is not limited to considering the
appropriate fault studies and time-current coordination
analysis of the protective devices and the conductor
damage curves. The overcurrent protection shall be
permitted to be provided by either 240.100(A)(1) or (A)(2).

(1) Overcurrent Relays and Current Transformers.

Circuit breakers used for overcurrent protection of 3-phase
circuits shall have a minimum of three overcurrent relay
elements operated from three current transformers. The
separate overcurrent relay elements (or protective
functions) shall be permitted to be part of a single
electronic protective relay unit.

On 3-phase, 3 -wire circuits, an overcurrent relay
element in the residual circuit of the current transformers
shall be permitted to replace one of the phase relay
elements.

An overcurrent relay element, operated from a current
transformer that links all phases of a 3-phase, 3-wire
circuit, shall be permitted to replace the residual relay
element and one of the phase-conductor current
transformers. Where the neutral gotldiictpi: is not
regrounded on the load side of the circuit as permitted in
250.184(B), the current transformer shall be permitted to
link all 3-phase conductors and the grounded circuit
conductor (neutral).

(2) Fuses. A fuse shall be connected in series with each
ungrounded conductor.

(B) Protective Devices. The protective device(s) shall be
capable of detecting and interrupting all values of current
that can occur at their location in excess of their trip-setting
or melting point.

(C) Conductor Protection. The operating time of the
protective device, the available short-circuit current, and
the conductor used shall be coordinated to prevent
damaging or dangerous temperatures in conductors or
conductor insulation under short-circuit conditions. .

240.101 Additional Requirements for Feeders.

(A) Rating or Setting of Overcurrent Protective
Devices. The continuous ampere rating of a fiise shall not
exceed three times the ampacity of the conductors. The
long-time trip element setting of a breaker or the minimum
trip setting of an electronically actuated fuse shall not
exceed six times the ampacity of the conductor. For fire
pumps, conductors shall be permitted to be protected for
overcurrent in accordance with 695.4(B).

(B) Feeder Taps. Conductors tapped to a feeder shall be
permitted to be protected by the feeder overcurrent device
where that overcurrent device also protects the tap
conductor.

AM^ICLEISO

Grounding and Bonding

I. General

250.1 Scope. This article covers general requirements for
grounding and bonding of electrical installations, and the
specific requirements in (1) through (6).

(1) Systems, circuits, and equipment required, permitted,
or not permitted to be grounded

(2) Circuit conductor to be grounded on grounded systems

(3) Location of grounding connections

(4) Types and sizes of grounding and bonding conductors
and electrodes

(5) Methods of grounding and bonding

(6) Conditions under which guards, isolation, or insulation
may be substituted for grounding

FPif:- See Figure 250.^; for infomiation on the organization
of Article 250 A:ivenng _^mpding ^ 3M J^

Part i General

Part li System
grounding

Part VI I! Direct-current

systems

Part X Grounding of

systems md circuits of

1 kV and over (high voltage)

Part III Grounding electrode

system and grounding

electrode conductor

Part iV Enclosure,

raceway, and service

cable grounding

Part VI Equipment

grounding and equipment

grounding conductors

Part V Bonding

Part VII Methods of

equipment grounding

Part IX Instruments,
meters, and relays

Figure 2504 Grounding and Bonding.

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2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.4

250.2 Definitions.

B0ndiii^£]fif mper^ Syslteni^ The connection between the
grounded circuit conductor and the equipment grounding
conductor at a separately derived system.

Effective Ground-Fault Current Path. An intentionally
constructed, low-impedance electrically conductive path
designed and intended to carry current under ground-fault
conditions from the point of a ground fault on a wiring
system to the electrical supply source and that facilitates the
operation of the overcurrent protective device or ground-
fault detectors on high-impedance grounded systems.

Ground Fault. An unintentional, electrically conducting
connection between an ungrounded conductor of an
electrical circuit and the normally non-current-carrying
conductors, metallic enclosures, metallic raceways,
metallic equipment, or earth.

Ground-Fault Current Path. An electrically conductive path
from the point of a ground fault on a wiring system through
normally non-current-carrying conductors, equipment, or
the earth to the electrical supply source.

FPN: Examples of ground-fault current paths could consist
of any combination of equipment grounding conductors,
metallic raceways, metallic cable sheaths, electrical
equipment, and any other electrically conductive material
such as metal water and gas piping, steel framing members,
stucco mesh, metal ducting, reinforcing steel, shields of
communications cables, and the earth itself

250.3 Application of Other Articles. For other articles
applying to particular cases of installation of conductors
and equipment, grounding and bonding requirements are
identified in Table 250.3 that are in addition to, or
modifications of, those of this article.

250.4 General Requirements for Grounding and
Bonding. The following general requirements identify
what grounding and bonding of electrical systems are
required to accomplish. The prescriptive methods
contained in Article 250 shall be followed to comply with
the performance requirements of this section.

(A) Grounded Systems.

(1) Electrical System Grounding. Electrical systems that
are grounded shall be connected to earth in a manner that
will limit the voltage imposed by lightning, line surges, or
unintentional contact with higher-voltage lines and that will
stabilize the voltage to earth during normal operation.

FPN: : jAn itdportant tbtisideimtion for htbittiig; : the imposed
yolt^^' is the ioutiiig of bdndirig and g^rounditig conductors sc>
jhat ihjey are iK>t any Ibnger ■ than necess^ tp compjete thd
conneciion without distiiibing ; ; the p^mahent paits of the
JnstallatibhM so that umieces^ary bends and;toops are avoided.;

(2) Grounding of Electrical Equipment. Normally non-
current-carrying conductive materials enclosing electrical
conductors or equipment, or forming part of such
equipment, shall be connected to earth so as to limit the
voltage to ground on these materials.

(3) Bonding of Electrical Equipment. NpilBally non-
current-carrying conductive materials enclosing electrical
conductors or equipment, or forming part of such
equipment, shall be connected together and to the electrical
supply source in a manner that establishes an effective
ground- fault current path.

(4) Bonding of Electrically Conductive Materials and
Other Equipment. Normally non-current-carrying
electrically conductive materials that are likely to become
energized shall be connected together and to the electrical
supply source in a manner that establishes an effective
ground- fault current path.

(5) Effective Ground-Fault Current Path. Electrical
equipment and wiring and other electrically conductive
material likely to become energized shall be installed in a
manner that creates a low-impedance circuit facilitating the
operation of the overcurrent device or ground detector for
high-impedance grounded systems. It shall be capable of
safely carrying the maximum ground-fault current likely to
be imposed on it from any point on the wiring system
where a ground fault may occur to the electrical supply
source. The earth shall not be considered as an effective
ground-fault current path.

(B) Ungrounded Systems.

(1) Grounding Electrical Equipment. Non-current-
carrying conductive materials enclosing electrical
conductors or equipment, or forming part of such
equipment, shall be connected to earth in a manner that will
limit the voltage imposed by lightning or unintentional
contact with higher-voltage lines and limit the voltage to
ground on these materials.

(2) Bonding of Electrical Equipment Non-current-
carrying conductive materials enclosing electrical conductors
or equipment, or forming part of such equipment, shall be
connected together and to the supply system grounded
equipment in a manner that creates a low-impedance path for
ground- fault current that is capable of carrying the maximum
fault current likely to be imposed on it.

(3) Bonding of Electrically Conductive Materials and
Other Equipment. Electrically conductive materials that
are likely to become energized shall be connected together
and to the supply system grounded equipment in a manner
that creates a low-impedance path for ground-fault current
that is capable of carrying the maximum fault current likely
to be imposed on it.

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250.4

ARTICLE 250 - GROUNDING AND BONDING

Table 250.3 Additional Grounding and Bonding Requirements

Conductor/Equipment

Article

Section

Agricultural buildings

Audio signal processing, amplification, and reproduction

equipment
Branch circuits
Cablebus
Cable trays
Capacitors

Circuits and equipment operating at less than 50 volts
Closed-loop and programmed power distribution
Communications circuits
Community antenna television and radio distribution

systems
Conductors for general wiring
Cranes and hoists

Electrically driven or controlled irrigation machines
Electric signs and outline lighting
Electrolytic cells
Elevators, dumbwaiters, escalators, moving walks,

wheelchair lifts, and stairway chair lifts
Fire alarm systems

Fixed electric heating equipment for pipelines and vessels
Fixed outdoor electric deicing and snow-melting

equipment
Flexible cords and cables
Floating buildings
Grounding-type receptacles, adapters, cord connectors,

and attachment plugs
Hazardous (classified) locations
Health care facilities

Induction and dielectric heating equipment
Industrial machinery
Information technology equipment
Intrinsically safe systems

Luminaires (lighting fixtures) and lighting equipment
Luminaires (fixtures), lampholders, and lamps
Marinas and boatyards
Mobile homes and mobile home park
Motion picture -and television studios and similar

locations
Motors, motor cn-cuits, and controllers
Natural ind artificially made bodies of water
Outlet, device, pull, and junction boxes; conduit bodies;

and fittings
Over 600 volts, nominal, underground wiring methods
Panelboards
Pipe organs

Radio and television equipment
Receptacles and cord connectors
Recreational vehicles and recreational vehicle parks
Services

Solar photovoltaic systems

Swimming pools, fountains, and similar installations
Switchboards and panelboards
Switches
Theaters, audience areas of motion picture and television

studios, and similar locations
Transformers and transformer vaults
Use and identification of grounded conductors
X-ray equipment

392
720
800

310
610

600
668
620

547.9 and 547.10
640.7

210.5,210.6,406.3

370.9

392.3(C), 392.7

460.10,460.27

780.3

820.93,820.100,820.103

675.11(C), 675.12, 675.13, 675.14, 675.15

760.9

427.29, 427.48

426.27

400.22, 400.23

553.8,553.10,553.11

406.9

500-517
517
665
670

410
550

430

650
810

551
230

680

200
660

645.15

504.50

410.17, 410.18, 410.20, 410.21, 410.105(B)

555.15

530.20, 530.64(B)

314.4,314.25

300.50(B)
408.40

406.3

690.41, 690.42, 690.43, 690.45, 690.47

408.3(D)
404.12
520.81

450.10

517.78

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2010 CaHfomia Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.20

(4) Path for Fault Current, Electrical equipment, wiring,
and other electrically conductive material likely to become
energized shall be installed in a manner that creates a low-
impedance circuit from any point on the wiring system to
the electrical supply source to facilitate the operation of
overcurrent devices should a second ground fault fromVa
diffemiit phase occur on the wiring system. The earth shall
not be considered as an effective fault-current path.

250.6 Objectionable Current.

(A) Arrangement to Prevent Objectionable Current.

The grounding of electrical systems, circuit conductors,
surge arresters, siw^-^mfccti^v^; devices^ and conductive
normally non-current-carrying metai paStS; of equipment
shall be installed and arranged in a manner that will prevent
objectionable current.

(B) Alterations to Stop Objectionable Current. If the use

of multiple grounding connections results in objectionable
current, one or more of the following alterations shall be
permitted to be made, provided that the requirements of
250.4(A)(5) or (B)(4) are met:

( 1 ) Discontinue one or more but not all of such grounding
connections.

(2) Change the locations of the grounding connections.

(3) Interrupt the continuity of the conductor or conductive
path causing the objectipliable currehti

(4) Take other suitable remedial and approved action.

(C) Temporary Currents Not Classified as Objectionable
Currents. Temporary currents resulting from accidental
conditions, such as ground faults, shall not be classified as
objectionable current for the purposes specified in 250.6(A)
and (B).

(D) Limitations to Permissible Alterations. The provisions
of this section shall not be considered as permitting
electronic equipment from being operated on ac systems or
branch circuits that are not cto^efed Jo^^^/^^^M^^
^^^^^^^c^y^^acfi:^ as required by this article. Currents
that introduce noise or data errors in electronic equipment
shall not be considered the objectionable currents
addressed in this section.

(E) Isolation of Objectionable Direct-Current Ground
Currents. Where isolation of objectionable dc ground currents
from cathodic protection systems is required, a listed ac
coupling/dc isolating device shall be permitted in the equipment
grounding BoilSl^tor path to provide an effective retum path for
ac ground-fault current while blocking dc current.

250.8 Connection of Grounding and Bonding
Equipment.

(A) Perimttedj M^ Groutidiiig conductors md

t^ndmgjxmipei^ shall :b^^ by one of &

folloWmg means:

(1) psted |)!^ssu!;e opiine

(2) Irjei&maito

(3) l*re3S#e cojj^^ and bonding
equipment

(4) Exothemic weldM

(5) Machine screwrtj^e fasteaers that engage not less than
two Uireads or are secured: with a nut

(6) Thread-forming imcjUne $cre^ that engage not lesfj
than two threads in tiie enclosure

(7) Connections ^Sat arejgaft of a ii$ted assemM^

(8) jOther listed meatis

J(B);'. Methods . ■- Not ■ . l^i^rinitSed.;.; \ 'd^vicel;: ox

itiSn^s that dependspleiy on soite shall riot be used!

250.10 Protection of Ground Clamps and Fittings.

Ground clamps or other fittings shall be approved for
general use without protection or shall be protected from
physical damage as indicated in (1) or (2) as follows:

(1) In installations where they are not likely to be damaged

(2) Where enclosed in metal, wood, or equivalent
protective covering

250.12 Clean Surfaces. Nonconductive coatings (such as
paint, lacquer, and enamel) on equipment to be grounded
shall be removed from threads and other contact surfaces to
ensure good electrical continuity or be connected by means
of fittings designed so as to make such removal unnecessary.

II. System Grounding

250.20 Alternating-Current Systems to Be Grounded.

Alternating-current systems shall be grounded as provided
for in 250.20(A), (B), (C), [pj,\6r: (E). Other systems shall
be permitted to be grounded. If such systems are grounded,
they shall comply with the applicable provisions of this
article.

FPN: An example of a system permitted to be grounded is a
comer-grounded delta transformer connection. See
250.26(4) for conductor to be grounded.

(A) Alternating-Current Systems of Less Than 50 Volts.

Ahernating-current systems of less than 50 volts shall be
grounded under any of the following conditions:

(1) Where supplied by transformers, if the transformer
supply system exceeds 150 volts to ground

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250.21

ARTICLE 250 - GROUNDING AND BONDING

(2) Where supplied by transformers, if the transformer
supply system is ungrounded

(3) Where installed outside as overhead conductors

(B) Alternating-Current Systems of 50 Volts to 1000
Volts. Alternating-current systems of 50 volts to 1000 volts
that supply premises wiring and premises wiring systems
shall be grounded under any of the following conditions:

(1) Where the system can be grounded so that the
maximum voltage to ground on the ungrounded
conductors does not exceed 150 volts

(2) Where the system is 3 -phase, 4- wire, wye connected in
which the neutral conductor is used as a circuit
conductor

(3) Where the system is 3 -phase, 4-wire, delta connected
in which the midpoint of one phase winding is used as
a circuit conductor

Alternating-current systems supplying mobile or portable
equipment shall be grounded as specified in 250.188.
Where supplying other than mobile or portable equipment,
such systems shall be permitted to be grounded.

(D) Separately Derived Systems. Separately derived
systems, as covered in 250.20(A) or (B), shall be grounded
as specified in 250.30(A). Where ^^ttalterciate sotircje siichi
^s:aii on-$ite generator is provided with traiisfer equiptnen^
that includes a grounded conductor that is BOt solidl}^
intetcotHiected to the seryice^supplied grounded conductor j
ihe alter^iate source (deiiyed syst^) sha^^
k9£9£4i¥^cewkh

FPN No. 1: An alternate ac power source such as an on-site
generator is not a separately derived system if the grounded
conductor is solidly interconnected to a service-supplied
system grounded conductor. An .exan^ie of su^h situations
is where alternate source transfer equipmerit does not
include a switching action in tfe grounded coBductox: and
allows it to remain splidly comi^e0te4 to the sorvice-sitppii^d
gtbutded-C0nduotbr;whesn the alternate sou^e : is ppmtim^
and suj)piying the load served;

FPN No. 2: For systems that are not separately derived and are
not required to be grounded as specified in 250.30, see 445.13
for minimum size of conductors that must carry fault current.

(E) Impedance Grounded Neutral Systems. Impedance
grounded neutral systems shall be grounded in accordance
with 250.36 or 250.186.

250.21 Alternating-Current Systems of 50 Volts to 1000
Volts Not Required to Be Grounded.

lAJ General* The folio w^ing ac systems of 50 volts to 1000
volts shall be permitted to be grounded but shall not be
required to be grounded:

(1) Electrical systems used exclusively to supply industrial
electric furnaces for melting, refining, tempering, and
the like

(2) Separately derived systems used exclusively for
rectifiers that supply only adjustable-speed industrial
drives

(3) Separately derived systems suppHed by transformers
that have a primary voltage rating less than 1000 volts,
provided that all the following conditions are met:

a. The system is used exclusively for control circuits.

b. The conditions of maintenance and supervision
ensure that only qualified persons service the
installation.

c. Continuity of control power is required.
m

(4) Other systems that are not required to be grounded in
accordance with the requirements of 250.20(B)

P) GrouBd Detectors* tlngrounded alternating cuitent
^sy^tems as permitted in 25Q.2lf A;)(l) through (A)(4:)
^bperatingat iiot less thaii^l^ exceeding J 000

!^Jts..y[iaH;h^ ;grou^^ the systemf

250.22 Circuits Not to Be Grounded. The following
circuits shall not be grounded:

(1) Circuits for electric cranes operating over combustible
fibers in Class III locations, as provided in 503.155

(2) Circuits in health care facilities as provided in 517.61
and 517.160

(3) Circuits for equipment within electrolytic cell working
zone as provided in Article 668

(4) Secondary circuits of lighting systems as provided in

411.5(A)

(5) Secondary drciiy^fS lighting^ as providedjn
||g,23(A)N(2)r "^^~ "^

250.24 Grounding Service-Supplied Alternating-
Current Systems.

(A) System Grounding Connections. A premises wiring
system supplied by a grounded ac service shall have a
grounding electrode conductor connected to the grounded
service conductor, at each service, in accordance with
250.24(A)(1) through (A)(5).

(1) General. The gmmdrtigy ch^^^ conductor
connection shall be made at any accessible point from the
load end of the service drop or service lateral to and
including the terminal or bus to which the grounded service
conductor is connected at the service disconnecting means.

FPN: See definitions of Service Drop and Service Lateral in
Article 100.

(2) Outdoor Transformer. Where the transformer
supplying the service is located outside the building, at
least one additional grounding connection shall be made
from the grounded service conductor to a grounding
electrode, either at the transformer or elsewhere outside the
building.

70-98

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.24

Exception: The additional grounding plectrade condifCtQf^
connection shall not he made on high-impedance grounded
neutral systems. The system shall meet the requirements of
250.36.

(3) Dual-Fed Services. For services that are dual fed
(double ended) in a common enclosure or grouped together
in separate enclosures and employing a secondary tie, a
single grounding electrode feoncfaibtS^ connection to the tie
point of the grounded conductor(s) from each power source
shall be permitted.

(4) Main Bonding Jumper as Wire or Busbar. Where
the main bonding jumper specified in 250.28 is a wire or
busbar and is installed from the grounded conductor
terminal bar or bus to the equipment grounding terminal
bar or bus in the service equipment, the grounding
electrode conductor shall be permitted to be connected to
the equipment grounding terminal, bar, or bus to which the
main bonding jumper is connected.

(5) Load-Side Grounding Connections. A grounded
con&c£or|$haH not be^ conae'cte3j(£^g^ non-^impnU
(caixying M^tal parts of equipment, tip equipment grounding
conductors) J or be reconnected Jo ground on the load side
of the service disconnecting means except as otherwise
permitted in this article.

FPN: See 250.30(A) for separately derived systems, 250.32
for connections at separate buildings or structures, and
250.142 for use of the grounded circuit conductor for
grounding equipment.

(B) Main Bonding Jumper. For a grounded system, an
unspliced main bonding jumper shall be used to connect the
equipment grounding conductor(s) and the service-disconnect
enclosure to the grounded conductor within the enclosure for
each service disconnect in accordance with 250.28.
Exception No. J: Where more than one service
disconnecting means is located in an assembly listed for
use as service equipment, an unspliced main bonding
jumper shall bond the grounded conductor(s) to the
assembly enclosure.

Exception No. 2: Impedance grounded neutral systems
shall be permitted to be connected as provided in 250.36
and 250.186.

(C) Grounded Conductor Brougiit to Service Equipment.
Where an ac system operating at less than 1000 volts is
grounded at any point, the grounded conductor(s) shall be run
to each service disconnecting means and shall be comect^td
bacj discdinnectiBg means grounded conductor(s) terminal or
bus. A main bonding jumper shall connect the grounded
conductor(s) to each service disconnecting means enclosure.
The grounded conductor(s) shall be installed in accordance
with 250.24(C)(1) through (C)(3).

Exception: Where more than one service disconnecting
means are located in d;Smgl§ assembly listed for use as
service equipment, it shall be permitted to run the
grounded conductor(s) to the assembly common grounde<i
hqndueipr(s). termiml -or^ bus-^.. 'The assembly shall '. include -d
>fwmjbon^^ -Cimnecting the "g>:oiinde4

Cpnductorfs) to the assembly enclosure.

(1) Routing and Sizing. This conductor shall be routed with
the phase conductors and shall not be smaller than the
required grounding electrode conductor specified in Table
250.66 but shall not be required to be larger than the largest
ungrounded service-entrance phase conductor. In addition,
for service-entrance phase conductors larger than 1 100 kcmil
copper or 1750 kcmil aluminum, the grounded conductor
shall not be smaller than I2V2 percent of the area of the
largest service-entrance phase conductor. The grounded
conductor of a 3 -phase, 3 -wire delta service shall have an
ampacity not less than that of the ungrounded conductors.

(2) Parallel Conductors. Where the service-entrance
phase conductors are installed in parallel, the size of the
grounded conductor shall be based on the total circular mil
area of the parallel conductors as indicated in this section.
Where installed in two or more raceways, the size of the
grounded conductor in each raceway shall be based on the
size of the ungrounded service-entrance conductor in the
raceway but not smaller than I/O AWG.

FPN: See 310.4 for grounded conductors connected in
parallel.

(3) High Impedance. The grounded conductor on a high-
impedance grounded neutral system shall be grounded in
accordance with 250.36.

(D) Grounding Electrode Conductor. A grounding
electrode conductor shall be used to connect the equipment
grounding conductors, the service-equipment enclosures,
and, where the system is grounded, the grounded service
conductor to the grounding electrode(s) required by Part III
of this article. [This j^o^Hu^ctec^ ^^w^d'm-BJC^:^c^^^

High-impedance grounded neutral system connections shall
be made as covered in 250.36.

FPN: See 250.24(A) for ac system grounding connections.

(E) Ungrounded System Grounding Connections. A
premises wiring system that is suppHed by an ac service
that is ungrounded shall have, at each service, a grounding
electrode conductor connected to the grounding
electrode(s) required by Part III of this article. The
grounding electrode conductor shall be connected to a
metal enclosure of the service conductors at any accessible
point from the load end of the service drop or service
lateral to the service disconnecting means.

2010 California Electrical Code

70-99

250.26

ARTICLE 250 - GROUNDING AND BONDING

250.26 Conductor to Be Grounded — Alternating-
Current Systems. For ac premises wiring systems, the
conductor to be grounded shall be as specified in the
following:

(1) Single-phase, 2-wire — one conductor

(2) Single-phase, 3 -wire — the neutral conductor

(3) Multiphase systems having one wire common to all
phases — the common conductor

(4) Multiphase systems where one phase is grounded —
one phase conductor

(5) Multiphase systems in which one phase is used as in
(2) — the neutral conductor

250.28 Main Bonding Juniper and System Bonding
Jumper. For a grounded system, main bonding jumpers
and system bonding jumpers shall be installed as follows:

(A) Material. Main bonding jumpers and system bonding
jumpers shall be of copper or other corrosion-resistant
material. A main bonding jumper and a system bonding
jumper shall be a wire, bus, screw, or similar suitable
conductor.

(B) Construction. Where a main bonding jumper or a
system bonding jumper is a screw only, the screw shall be
identified with a green finish that shall be visible with the
screw installed.

(C) Attachment. Main bonding jumpers and system
bonding jumpers shall be connected in the manner
specified by the applicable provisions of 250.8.

(D) Size. Main bonding jtynp6rs and system bondktg
jumpers shall be sized in accordance with 250.28(f>)(i)
throu^(OX3):

(1) General. Main bonding jumpers and system bonding
jumpers shall not be smaller than the sizes shown in Table
250.66. Where the supply conductors are larger than 1100
kcmil copper or 1750 kcmil aluminum, the bonding jumper
shall have an area that is not less than I2V2 percent of the
area of the largest phase conductor except that, where the
phase conductors and the bonding jumper are of different
materials (copper or aluminum), the minimum size of the
bonding jumper shall be based on the assumed use of phase
conductors of the same material as the bonding jumper and
with an ampacity equivalent to that of the installed phase
conductors.

(2)_ Mam Bonding Jumper for^Serw Thari

bn|:J&5closiire, Where ^:spm(^[ consists of motia than a;
^mglC; enclosure j as^^ PMmit|ei| ^jja;^^^^ the-/ mad

hgndmBjumj>ct for^- each; jenc|pji^^ mmd^^M

l^rcordance' ^ ^ , with \25B2^py0J$^ ;. on the , ^ largesl
imgrounded service conduc^^ semng that enclosure.

i[3)';fSe|jarately _ ^ More^ J]hatfl6'iiii

tencios«re. Where ?^J^pp^tntQi£d^^ systeni supplies
more than, a single eriplosure, the system bonding jumper
for each enclosure shall be sized m accoi'dance with
25p.28(D)(l) based |n , the largest ungroimded feedeii
conductor serving th|t enclosure, or a single system
jbonding jumper shall % installed at the source and sized in
kccordance w^ 25().2|(r))(l) tes^ equiyalent size!

joOhe^largest supj)ly

fe&M: |h^, ^^P^P^^i ih|:5?ff4sp„^55(ngi conductors^'of .eacS
bet:

250.30 Grounding Separately Derived Alternating-
Current Systems.

(A) Grounded Systems. A separately derived ac system that
is grounded shall comply with 250.30(A)(1) through (A)(8).
Except as otherwise p^rmittey in this article, a pounded
Conductor s^^ bejcormec^y to^^n^^ nonTHCurrerit:^

jCOTyiiig metal parts q^equipmen^^ grquaiditig

bo^ductors, or be recqnnepted^ to^^qimd on the loa^^^^
jtheppint of grounding of a^ep^aratef>; derived system,

FPN: See 250.32 for connections at separate buildings or
structures, and 250.142 for use of the grounded circuit
conductor for grounding equipment.

Exception: Impedance grounded neutral system grounding
connections shall be made as specified in 250.36 or 250.186.
(1) System Bonding Jumper. An unspHced system
bonding jumper in compliance with 250.28(A) through (D)
that is sized based on the derived phase conductors shall be
used to connect the equipment grounding conductors of the
separately derived system to the grounded conductor. This
connection shall be made at any single point on the
separately derived system from the source to the first
system disconnecting means or overcurrent device, or it
shall be made at the source of a separately derived system
that has no disconnecting means or overcurrent devices.
Exception No. 1: For separately derived systems that are
dual fed (double ended) in a common enclosure or grouped
together in separate enclosures and employing a secondary
tie, a single system bonding jumper connection to the tie
point of the grounded circuit conductors from each power
source shall be permitted.

Exception No. 2: A system bonding jumper at both the
source and the first disconnecting means shall be permitted
where doing so does not establish a parallel path for the
grounded conductor. Where a grounded conductor is used
in this manner, it shall not be smaller than the size
specified for the system bonding jumper but shall not be
required to be larger than the ungrounded conductor (s).
For the purposes of this exception, connection through the
earth shall not be considered as providing a parallel path.

70-100

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.30

Exception No. 3: The size of the system bonding jumper
for a system that supplies a Class 1, Class 2, or Class 3
circuit, and is derived from a transformer rated not more
than 1000 volt-amperes, shall not be smaller than the
derived phase conductors and shall not be smaller than 14
A WG copper or 12 A WG aluminum.

(2) Equipment Bonding Jumper Size. Where %xi
equipment bonding jumper of the wire type is run with the
derived phase conductors from the source of a separately
derived system to the first disconnecting means, it shall be
sized in accordance with 250.102(C), based on the size of
the derived phase conductors.

(3) Grounding Electrode Conductor, Single Separately
Derived System. A grounding electrode conductor for a single
separately derived system shall be sized in accordance with
250.66 for the derived phase conductors and shall be used to
connect the grounded conductor of the derived system to the
grounding electrode as specified in 250.30(A)(7). This
connection shall be made at the same point on the separately
derived system where the system bonding jumper is poimictedi
Exception No. 1: Where the system bonding jumper
specified in 250, 30(A)(1) is a wire or busbar, it shall be
permitted to connect the grounding electrode conductor to
the equipment grounding terminal, bar, or bus, provided
the equipment grounding terminal, bar, or bus is of
sufficient size for the separately derived system.
Exception No, 2: Where a separately derived system
originates in listed equipment suitable as service equipment,
the grounding electrode conductor from the service or feeder
equipment to the grounding electrode shall be permitted as
the grounding electrode conductor for the separately derived
system, provided the groimding electrode conductor is of
sufficient size for the separately derived system. Where the
equipment grounding bus internal to the equipment is not
smaller than the required grounding electrode conductor for
the separately derived system, the grounding electrode
connection for the separately derived system shall be
permitted to be made to the bus.

Exception No. 3: A grounding electrode conductor shall
not be required for a system that supplies a Class 1, Class
2, or Class 3 circuit and is derived from a transformer
rated not more than 1000 volt-amperes, provided the
grounded conductor is bonded to the transformer frame or
enclosure by a jumper sized in accordance with
250.30(A)(1), Exception No. 3, and the transformer frame
or enclosure is grounded by one of the means specified in
250.134.

(4) Grounding Electrode Conductor, Multiple
Separately Derived Systems. Where more than one
separately derived system is installed, it shall be
permissible to connect a tap from each separately derived
system to a common grounding electrode conductor. Each
tap conductor shall connect the grounded conductor of the
separately derived system to the common grounding

electrode conductor. The grounding electrode conductors

and taps shall comply with 250.30(A)(4)(a) through

(A)(4)(c). This coxmectipn shall fei^^

pn the separately derived system where thie system bonding

jumper is installed;

Exception No. 1: Where the system bonding jumper

specified in 250.30(A)(1) is a wire or busbar, it shall be

permitted to connect the grounding electrode conductor to

the equipment grounding terminal, bar, or bus, provided

the equipment grounding terminal, bar, or bus is of

sufficient size for the separately derived system.

Exception No. 2: A grounding electrode conductor shall not
be required for a system that supplies a Class 1, Class 2, or
Class 3 circuit and is derived from a transformer rated not
more than 1000 volt-amperes, provided the system grounded
conductor is bonded to the transformer frame or enclosure
by a jumper sized in accordance with 250.30(A)(1),
Exception No. 3 and the transformer frame or enclosure is
grounded by one of the means specified in 250.134.

(a) Common Grounding Electrode Conductor Size.
The common grounding electrode conductor shall not be
smaller than 3/0 AWG copper or 250 kcmil aluminum.

(b) Tap Conductor Size. Each tap conductor shall be
sized in accordance with 250.66 based on the derived phase
conductors of the separately derived system it serves.

Exception: Where a separately derived system originates
in listed equipment suitable as service equipment, the
grounding electrode conductor from the service or feeder
equipment to the grounding electrode shall be permitted as
the grounding electrode conductor for the separately
derived system, provided the grounding electrode
conductor is of sufficient size for the separately derived
system. Where the equipment ground bus internal to the
equipment is not smaller than the required grounding
electrode conductor for the separately derived system, the
grounding electrode connection for the separately derived
system shall be permitted to be made to the bus.

(c) Connections. All tap connections to the common
grounding electrode conductor shall be made at an
accessible location by one of the following methods:

(1) A listed connector.

(2) Listed connections to aluminum or copper busbars not
less than 6 mm x 50 mm (% in. x 2 in.). Where
aluminum busbars are used, the installation shall
comply with 250.64(A).

(3) The exothermic welding process.

Tap conductors shall be connected to the common
grounding electrode conductor in such a manner that the
common grounding electrode conductor remains without a
splice or joint.

2010 California Electrical Code

70-101

250.32

ARTICLE 250 - GROUNDING AND BONDING

(5) Installation. The installation of all grounding electrode
conductors shall comply with 250.64(A), (B), (C), and (E).

(6) Bonding. Structural steel and metal piping shall be

derived system in accprdaace with 250/1 p4(p)i

(7) Grounding Electrode. The grounding electrode shall
be as near as practicable to and preferably in the same area
as the grounding electrode conductor connection to the
system. The grounding electrode shall be the nearest one of
the following:

(1) Metal water pipe grounding electrode as specified in
250.52(A)(1)

(2) Structural metal grounding electrode as specified in

250.52(A)(2)

Exception No, 1: Any of the other electrodes identified in
250.52(A) shall be used where the electrodes specified by
25030(A)(7) are not available.

Exception No. 2 to (1) and (2): Where a separately derived
system originates in listed equipment suitable for use as
service equipment, the grounding electrode used for the
service or feeder equipment shall be permitted as the
grounding electrode for the separately derived system.

FPN: See 250.104(D) for bonding requirements of interior
metal water piping in the area served by separately derived
systems.

(8) Grounded Conductor. Where a grounded conductor
is installed and the system bonding jumper connection is
not located at the source of the separately derived system,
250.30(A)(8)(a), (A)(8)(b), and (A)(8)(c) shall apply.

(a) Routing and Sizing. This conductor shall be routed
with the derived phase conductors and shall not be smaller
than the required grounding electrode conductor specified
in Table 250.66 but shall not be required to be larger than
the largest ungrounded derived phase conductor. In
addition, for phase conductors larger than 1100 kcmil
copper or 1750 kcmil aluminum, the grounded conductor
shall not be smaller than I2V2 percent of the area of the
largest derived phase conductor. The grounded conductor
of a 3 -phase, 3 -wire delta system shall have an ampacity
not less than that of the ungrounded conductors.

(b) Parallel Conductors. Where the derived phase
conductors are installed in parallel, the size of the grounded
conductor shall be based on the total circular mil area of
the parallel conductors, as indicated in this section. Where
installed in two or more raceways, the size of the grounded
conductor in each raceway shall be based on the size of the
ungrounded conductors in the raceway but not smaller than
1/0 AWG.

FPN: See 310.4 for grounded conductors connected in
parallel.

(c) Impedance Grounded System. The grounded
conductor of an impedance grounded neutral system shall
be installed in accordance with 250.36 or 250.186.

(B) Ungrounded Systems. The equipment of an
ungrounded separately derived system shall be grounded as
specified in 250.30(B)(1) and (B)(2).

(1) Grounding Electrode Conductor. A grounding
electrode conductor, sized in accordance with 250.66 for
the derived phase conductors, shall be used to connect the
metal enclosures of the derived system to the grounding
electrode as specified in 250.30(B)(2). This connection
shall be made at any point on the separately derived system
from the source to the first system disconnecting means.

(2) Grounding Electrode. Except as permitted by 250.34
for portable and vehicle-mounted generators, the grounding
electrode shall comply with 250.30(A)(7).

250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).

(A) Grounding Electrode. Building(s) or structure(s)
supplied by feeder(s) or branch circuit(s) shall have a
grounding electrode or grounding electrode system
installed in accordance with part III prA^ 250, The
grounding electrode conductor(s) shall be connected in
accordance with 250.32(B) or (C). Where there is no
existing grounding electrode, the grounding electrode(s)
required in 250.50 shall be installed.

Exception: A grounding electrode shall not be required
where only a single branch circuit, mcluding pmult^^
Pl93<^h.£k£¥¥> supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non-current-carrying metal
parts of equipment.

(B) Grounded Systems. For a grounded system at the
separate building or structure, ^ equipment grounding
conductor as described in 250.118 shall be run with the
supply conductors and § connected to the building or
structure disconnecting means and to the grounding
electrode(s). The equipment grounding conductor shall be
used for grounding or bonding of equipment, structures, or
frames required to be grounded or bonded. The equipment
grounding conductor shall be sized in accordance with
250.122, Any installed grounded conductor shall not be
connected to the equipment grounding conductor or to the
grounding electrode(s).

Exceptionf For existing premUes^ wiring system^ = Qnly, \ the.
grounded conductor run with fhe-Mppjy. to the buttding or
stmcture shall be pefjnitted toh0€^ building

0r stmctur^ disionnectingjineaps; and to the grounding
eiectr€!de(s) andshdMbeiisedfor gm^ or bonding of

equipment, structures^ or: fiames^t;eguired^^^^ be grounded
or ponded where all ih^^requitemev^^
are met:

70-102

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

i50J5

(1) An equipment grounding conductor is not run with
the supply to the building or structure.

(2) There are no continuous metallic paths bonded to
the grounding system in each building or structure
involved.

(3) Ground-fault protection of equipment has not been
installed on the supply side of the feeder (s).

^Where\ '-the; gromde(i condtdctor is -usedrfi^r gr0tmiing in
accordmtSe with the provision of this exc^ptipn, the size of
the grounded conductor shall not be smaller than the
larger of either of the following:

(1) That required by 220.61

(2) That required by 250. 122

(D) Disconnecting Means Located in Separate Building
or Structure on the Same Premises. Where one or more
disconnecting means supply one or more additional
buildings or structures under single management, and
where these disconnecting means are located remote from
those buildings or structures in accordance with the
provisions of 225.32, Exception No. 1 and No. 2,
760J2(B)(6);MLniB)(5). or 7011 i,^ all of the following
conditions shall be met:

(1) The connection of the grounded conductor to the
grounding electrode, b nbrmaliyr&|i7ttCBipr

rnetaij!. = pSrS; ; : iof r ^(^rpm^n% 1; or K;io K J|g^.i: :eqdpm^
grburi&g pohd^^ at a separate building or structure
shall not be made.

(2) An equipment grounding conductor for grounding and.
bondmg any aomiallyi non-current-carrying metal
part$' of equipment, interior metal piping systems, and
building or structural metal frames is run with the
circuit conductors to a separate building or structure
and fe<>taieGteJ to existing grounding electrode(s)
required in Part III of this article, or, where there are
no existing electrodes, the grounding electrode(s)
required in Part III of this article shall be installed
where a separate building or structure is supplied by
more than one branch circuit.

(3) ilfe;: cogtgptito^;]^^ the equipment grounding
conductor aM the grounding electrode at a separate
building or structure shall be made in a junction box,
panelboard, or similar enclosure located immediately
inside or outside the separate building or structure.

(E) Grounding Electrode Conductor. The size of the

grounding electrode conductor to the grounding
electrode(s) shall not be smaller than given in 250.66,
based on the largest ungrounded supply conductor. The
installation shall comply with Part III of this article.

250.34 Portable and Vehicle-Mounted Generators.

(A) Portable Generators. The frame of a portable
generator shall not be required to be connected to a
grounding electrode as defined in 250.52 for a system
supplied by the generator under the following conditions:

(1) The generator supplies only equipment mounted on the
generator, cord-and-plug-connected equipment through
receptacles mounted on the generator, or both, and

(2) The normaiiy non-current-carrying metal parts of
equipment and the equipment grounding conductor
terminals of the receptacles are g<Hmecte<| to the
generator frame.

(B) Vehicle-Mounted Generators. The frame of a vehicle
shall not be required to be connected to a grounding
electrode as defined in 250.52 for a system supphed by a
generator located on this vehicle under the following
conditions:

(1) The frame of the generator is bonded to the vehicle
frame, and

(2) The generator supplies only equipment located on the
vehicle or cord-and-plug-connected equipment through
receptacles mounted on the vehicle, or both equipment
located on the vehicle and cord-and-plug-connected
equipment through receptacles mounted on the vehicle
or on the generator, and

(3) The normal^ non-current-carrying metal parts of
equipment and the equipment grounding conductor
terminals of the receptacles are 'ppwdpipA to the
generator frame.

(C) Grounded Conductor Bonding. A system conductor
that is required to be grounded by 250.26 shall be
pqnnected to the generator frame where the generator is a
component of a separately derived system.

FPN: For grounding portable generators supplying fixed
wiring systems, see 250.20(D).

250.35 Pernaaaentiy liistBiled Generators. A conductor
that provides an effqctive ground-fault current pa<ih shall be
installed with the supply eondudors from a permanently
installed gen€rator(s) to th^ fkst discpmiectm^^
;qicc0rdance with (A) or (B)J

(A) ''Separately- derived ':Systeniv Where; ;Se';geaeratdr; i$
iristalledias a sepiaratelyjderived systera^ th^^^^^
m 25030 shall apply^ ' '^

i(P) Noiiseparately Derived System* Where the generator
is ■ not installed as a separately dOTVedsystarrij an
equipnaent bonding jmnper shall be mstalied between the
generator equipment grotinding terminal; and the: equipnient
^rbtmdiiig terminal or; bus of the; etM^loske: df jsupplied
^dis connecting niean(s) in accbrda^^^ (B)( l;);;Qt £B)(2):

2010 California Electrical Code

70-103

250.36

ARTICLE 250 - GROUNDING AND BONDING

(1) Supply Side of Geneirator Overcurrent Device* The

equipment boeding jumper on the supply sid^ of each
generator oyercurreiit device shall be sized in accordance
with 250.102(C) based ori the size of the conductors
isuppiied by the generator

1(2) \ >Load Side of : (Jeneratbr Overcurrent ^ Device* ._ The
eqiitpnieiit groimdiiig;;c^^^^ on the load side of each

generator overcurrent device shall be sized in accordance
with ,250J02(D) baged on the rating of the overcurrent
device supplied:

250.36 High-Impedance Grounded Neutral Systems.

High-impedance grounded neutral systems in which a
grounding impedance, usually a resistor, limits the ground-
fault current to a low value shall be permitted for 3 -phase
ac systems of 480 volts to 1000 volts where all the
following conditions are met:

(1) The conditions of maintenance and supervision ensure
that only qualified persons service the installation.

(2) Ground detectors are installed on the system.

(3) Line- to-neutral loads are not served.

High-impedance grounded neutral systems shall
comply with the provisions of 250.36(A) through (G).

(A) Grounding Impedance Location. The grounding
impedance shall be installed between the grounding
electrode conductor and the system neutral point. Where a
neutral point is not available, the grounding impedance shall
be installed between the grounding electrode conductor and
the neutral point derived from a grounding transformer.

(B) Grounded System Conductor. The grounded system

conductor from the neutral point of the transformer or
generator to its connection point to the grounding
impedance shall be fully insulated.

The grounded'^ systerri conductor shall have an
ampacity of not less than the maximum current rating of
the grounding impedance. In no case shall the pounded
system conductor be smaller than 8 AWG copper or 6
AWG aluminum or copper-clad aluminum.

FPN: The impedance is normally selected to limit the
ground-fault current to a value slightly greater than or equal
to the capacitive charging current of the system. This value
of impedance will also limit transient overvoltages to safe
values. For guidance, refer to criteria for limiting transient
overvoltages in ANSI/IEEE 142-1991, Recommended
Practice for Grounding of Industrial and Commercial
Power Systems.

(D) Neutral Point to Grounding Impedanci^ Conductor
Routing. The conductor connecting the neutral point of the
transformer or generator to the grounding impedance shall

be permitted to be installed in a separate raceway frpm the
ungrounded conductpifs J It shall not be required to run this
conductor with the phase conductors to the first system
disconnecting means or overcurrent device.

(E) Equipment Bonding Jumper. The equipment bonding
jumper (the connection between the equipment grounding
conductors and the grounding impedance) shall be an
unspliced conductor run from the first system
disconnecting means or overcurrent device to the grounded
side of the grounding impedance.

(F) Grounding Electrode Conductor Location. The

grounding electrode conductor shall be CQnnectedi at any
point from the grounded side of the grounding impedance
to the equipment grounding connection at the service
equipment or first system disconnecting means.

(G) Equipment Bonding Jumper Size. The equipment
bonding jumper shall be sized in accordance with (1) or (2)

as follows:

(1) Where the grounding electrode conductor connection is
made at the grounding impedance, the equipment
bonding jumper shall be sized in accordance with
250.66, based on the size of the service entrance
conductors for a service or the derived phase
conductors for a separately derived system.

(2) Where the grounding electrode conductor is connected
at the first system disconnecting means or overcurrent
device, the equipment bonding jumper shall be sized
the same as the neutral conductor in 250.36(B).

III. Grounding Electrode System and Grounding
Electrode Conductor

250.50 Grounding Electrode System. All grounding
electrodes as described in 250.52(A)(1) through (A)(7) that
are present at each building or structure served shall be
bonded together to form the grounding electrode system.
Where none of these grounding electrodes exist, one or
more of the grounding electrodes specified in 250.52(A)(4)
through (A)(8) shall be installed and used.

Exception: Concrete-encased electrodes of existing
buildings or structures shall not be required to be part of
the grounding electrode system where the steel reinforcing
bars or rods are not accessible for use without disturbing
the concrete.

250.52 Grounding Electrodes.

(A) Electrodes Permitted for Grounding.

(1) Metal Underground Water Pipe. A metal underground
water pipe in direct contact with the earth for 3.0 m (10 ft)
or more (including any metal well casing bonded to the
pipe) and electrically continuous (or made electrically
continuous by bonding around insulating joints or
insulating pipe) to the points of connection of the
grounding electrode conductor and the bonding conductors.

70-104

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.53

Interior metal water piping located more than 1.52 m (5 ft)
from the point of entrance to the building shall not be used
as a part of the grounding electrode system or as a
conductor to interconnect electrodes that are part of the
grounding electrode system.

Exception: In industrial, commercial, and institutional
buildings or structures where conditions of maintenance
and supervision ensure that only qualified persons service
the installation, interior metal water piping located more
than 1.52 m (5 ft) from the point of entrance to the building
shall be permitted as a part of the grounding electrode
system or as a conductor to interconnect electrodes that
are part of the grounding electrode system, provided that
the entire length, other than short sections passing
perpendicularly through walls, floors, or ceilings, of the
interior metal water pipe that is being used for the
conductor is exposed.

(2) Metal Frame of the Building or Structure. The metal
frame of the building or structure tjc^ihmwmQi^AO: the

earth by^fiJdfSie fol jewing m^hod$|

(1) 3.0 m (10 ft) or more of a single structural metal
member in direct contact with the earth or encased in
concrete that is in direct contact with the earth

(2) jCdmecting' the structural metal frame to the
ranflrciBg: bars of a;„ concrete-encased d as

25(K

(3) Bond^ing the Srocturaj rnetal frame to one or moire of
the glgunding electrodes as defined m250.52(^^^ or
(AXi^Siat comply with 256,5^

(4) Other approved means of establishing a connection to
earth

(3) Concrete-Encased Electrode. An electrode encased
by at least 50 mm (2 in.) of concrete, located jborizqntaily
near the bottom pr verticaliy» and wiJiin that porttoij of a
concrete foundation or footing that is in direct contact with
the earth, consisting of at least 6.0 m (20 ft) of one or more
bare or zinc galvanized or other electrically conductive
coated steel reinforcing bars or rods of not less than 1 3 mm
(V2 in.) in diameter, or consisting of at least 6.0 m (20 ft) of
bare copper conductor not smaller than 4 AWG.
Reinforcing bars shall be permitted to be bonded together
by the usual steel tie wires or other effective means, jwfeg

WldiBg:|f Supti^ .to:|)oiWi only

bneip.t6;4ej^ouijd eleotxode^ §yste;m,

(4) Ground Ring. A ground ring encircling the building or
structure, in direct contact with the earth, consisting of at

least 6.0 m (20 ft) of bare copper conductor not smaller
than 2 AWG.

(5) Rod and Pipe Electrodes. Rod and pipe electrodes
shall not be less than 2.44 m (8 ft) in length and shall
consist of the following materials.

(a) jGxomdiiig elecfrodes of pipe or conduit shall not
be smaller than metric designator 21 (trade size Va) and,
where of steel, shall have the outer surface galvanized or
otherwise metal-coated for corrosion protection.

(b) Grounding eleqtodes of ^stmhles?- steel and coppe;?
!or ziiiC coated steel shall be at least 15.87 mm (5/8 in.) in
diameter, unless listed and not less than 12.70 mm (V2 in.)
in diameter.

|<|) ^ Other Listed J^^ groundinl

Jdectrodes shall |)ei>ermtted.;

(7) Plate Electrodes. Each plate electrode shall expose not
less than 0.186 m2 (2 ft2) of surface to exterior soil.
Electrodes of iron or steel plates shall be at least 6.4 mm QA
in.) in thickness. Electrodes of nonferrous metal shall be at
least 1.5 mm (0.06 in.) in thickness.

(8) Other Local Metal Underground Systems or
Structures. Other local metal underground systems or
structures such as piping systems, underground tanks, and
underground metal well casings that are not bonded to a
metal water pipe.

(B) Not Permitted for lUse as Grounding EleciroSi^ The
following systems and materials shall not be used as
grounding electrodes:

(1) Metal underground gas piping systemf

(2) Aluminum

FPN: See 250.104(B) for bonding requirements of gas piping.

250.53 Grounding Electrode System Installation. FPN:
See 547.9 and 547.10 for special grounding and bonding
requirements for agricultural buildings.

(A) Rod, Pipe, and Plate Electrodes. Where practicable,
rod, pipe, and plate electrodes shall be embedded below
permanent moisture level. Rod, pipe, and plate electrodes
shall be fi*ee from nonconductive coatings such as paint or
enamel.

(B) Electrode Spacing. Where more than one of the
electrodes of the type specified in 250.52(A)(5) or (A)(7)
are used, each electrode of one grounding system
(including that used for air terminals) shall not be less than
1.83 m (6 ft) from any other electrode of another grounding
system. Two or more grounding electrodes that are bonded
together shall be considered a single grounding electrode
system.

2010 California Electrical Code

70-105

250.54

ARTICLE 250 - GROUNDING AND BONDING

(C) Bonding Jumper. The bonding jumper(s) used to
connect the grounding electrodes together to form the
grounding electrode system shall be installed in accordance
with 250.64(A), (B), and (E), shall be sized in accordance
with 250.66, and shall be connected in the manner
specified in 250.70.

(D) Metal Underground Water Pipe. Where used as a
grounding electrode, metal underground water pipe shall
meet the requirements of 250.53(D)(1) and (D)(2).

(1) Continuity. Continuity of the grounding path or the
bonding connection to interior piping shall not rely on
water meters or filtering devices and similar equipment.

(2) Supplemental Electrode Required. A metal
underground water pipe shall be supplemented by an
additional electrode of a type specified in 250.52(A)(2)
through (A)(8). Where the supplemental electrode is a rod,
pipe, or plate type, it shall comply with 250.56. The
supplemental electrode shall be permitted to be bonded to
the grounding electrode conductor, the grounded service-
entrance conductor, the nonflexible grounded service
raceway, or any grounded service enclosure.

Exception: The supplemental electrode shall be permitted
to be bonded to the interior metal water piping at any
convenient point as covered in 250.52(A)(1), Exception.

(E) Supplemental Electrode Bonding Connection Size.

Where the supplemental electrode is a rod, pipe, or plate
electrode, that portion of the bonding jumper that is the
sole connection to the supplemental grounding electrode
shall not be required to be larger than 6 AWG copper wire
or 4 AWG aluminum wire.

(F) Ground Ring. The ground ring shall be buried at a depth
below the earth's surface of not less than 750 mm (30 in.).

(G) Rod and Pipe Electrodes. The electrode shall be
installed such that at least 2.44 m (8 ft) of length is in
contact with the soil. It shall be driven to a depth of not less
than 2.44 m (8 ft) except that, where rock bottom is
encountered, the electrode shall be driven at an oblique
angle not to exceed 45 degrees from the vertical or, where
rock bottom is encountered at an angle up to 45 degrees,
the electrode shall be permitted to be buried in a trench that
is at least 750 mm (30 in.) deep. The upper end of the
electrode shall be flush with or below ground level unless
the aboveground end and the grounding electrode
conductor attachment are protected against physical
damage as specified in 250.10.

(H) Plate Electrode. Plate electrodes shall be installed not
less than 750 mm (30 in.) below the surface of the earth.

250.54 Auxiliary Grounding Electrodes. One or more
grounding electrodes shall be permitted to be connected to
the equipment grounding conductors specified in 250.118
and shall not be required to comply with the electrode
bonding requirements of 250.50 or 250.53(C) or the
resistance requirements of 250.56, but the earth shall not be
used as an effective ground-fault current path as specified
in 250.4(A)(5) and 250.4(B)(4).

250.56 Resistance of Rod, Pipe, and Plate Electrodes. A

single electrode consisting of a rod, pipe, or plate that does not
have a resistance to ground of 25 ohms or less shall be
augmented by one additional electrode of any of the types
specified by 250.52(A)(4) through (A)(8). Where multiple rod,
pipe, or plate electrodes are installed to meet the requirements
of this section, they shall not be less than 1.8 m (6 ft) apart.

FPN: The paralleling efficiency of rods longer than 2.5 m (8
ft) is improved by spacing greater than 1.8 m (6 ft).

250.58 Common Grounding Electrode. Where an ac
system is connected to a grounding electrode in or at a
building or structure, the same electrode shall be used to
ground conductor enclosures and equipment in or on that
building or structure. Where separate services, feeders, or
branch circuits supply a building and are required to be
connected to a grounding electrode(s), the same grounding
electrode(s) shall be used.

Two or more grounding electrodes that are bonded
together shall be considered as a single grounding electrode
system in this sense.

250.60 Use of Air Terminals. Air terminal conductors and
driven pipes, rods, or plate electrodes used for grounding air
terminals shall not be used in lieu of the grounding electrodes
required by 250.50 for grounding wiring systems and
equipment. This provision shall not prohibit the required
bonding together of grounding electrodes of different systems.

FPN No. 1: See 250.106 for spacing from air terminals. See
800.100(D), 810.21(J), and 820.100(D) for bonding of
electrodes.

FPN No. 2: Bonding together of all separate grounding
electrodes will limit potential differences between them and
between their associated wiring systems.

250.62 Grounding Electrode Conductor Material. The

grounding electrode conductor shall be of copper,
aluminum, or copper-clad aluminum. The material selected
shall be resistant to any corrosive condition existing at the
installation or shall be suitably protected against corrosion.
The conductor shall be solid or stranded, insulated,
covered, or bare.

70-106

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.64

250.64 Grounding Electrode Conductor Installation.

Grounding electrode conductors at: the service/ at eacH
6uM4mg orstructiire Where supplied b^^ a feedef{s) .or
breach cifcuit(s)j; or at a separatel^^^^^ shall be

installed as specified in 250.64(A) through (F).

(A) Aluminum or Copper-Clad Aluminum Conductors.

Bare aluminum or copper-clad aluminum grounding
conductors shall not be used where in direct contact with
masonry or the earth or where subject to corrosive
conditions. Where used outside, aluminum or copper-clad
aluminum grounding conductors shall not be terminated
within 450 mm (18 in.) of the earth.

(B) Securing and Protection Against Physical Damage.

Where exposed, a grounding electrode conductor or its
enclosure shall be securely fastened to the surface on which
it is carried. A 4 AWG or larger copper or aluminum
grounding electrode conductor shall be protected where
exposed to physical damage. A 6 AWG grounding
electrode conductor that is free from exposure to physical
damage shall be permitted to be run along the surface of
the building construction without metal covering or
protection where it is securely fastened to the construction;
otherwise, it shall be in rigid metal conduit, intermediate
metal conduit, rigid nonmetallic conduit, electrical metallic
tubing, or cable armor. Grounding electrode conductors
smaller than 6 AWG shall be in rigid metal conduit,
intermediate metal conduit, rigid nonmetallic conduit,
electrical metallic tubing, or cable armor.

(C) Continuous. Grounding electrode conductor(s) shall
be installed in one continuous length without a splice or
joint except as permitted in (1) and (2):

(1) Sphcing shall be permitted only by irreversible
compression-type connectors listed as grounding and
bonding equipment or by the exothermic welding process.

(2) Sections of busbars shall be permitted to be connected
together to form a grounding electrode conductor.

(D) Serfice with Multiple DIscotitiecting Means
Enclosures* Where a service consists of more than a single
enclosure as permitted in 230Jl(A)j grounding eljectrode
connections shall be made in accordance with (P){1),
(D)(2), or fD)(3).

(f) :^Groundm^ 'Whcxe fte

somc^mimimlUQ by_^_230;4D^_Exc^^^^ No.'

2; a ; cpmnion grounding electrode conductor and grounding
electrode ponductor taps sliall be installed The common
grounding electrode conductor shall be sized in accordance
with 250,^6, based on the sum of the circular mil area of
the largest ungrounded service-entrance (^on4uctor(s).
Where the service-entrance conduc^^^^
a^ $e|-vice ?drop,,or^iyioe ;|ato jhej;pjHnmon ' ;^^^
electrode bonductpt shali be sized in accordance with Table

25 0,66 J Mote 1. A tap conductor shall extend to the inside
bf each service disconnecting means enclosure. The
grounding electrode conductor taps shall be sized in
accordance with 250^66 for; the largest cQhductor serving
the individual enclosure., the tap qondnctqrs; shall be
cpimecfed to the^ coinmon : grounding electro&,cond^
by ^exothermic welding or with cphnecjors' (listed as
grounding and bonding equipment in such a manner that
pie common grounding ele^^rode conductor remains
without a splice or joint.

(2) ; Indrndual Grounding Electrode Conductors* A

grounding electrode ^conduct^^ be connected between

i?§ ,,8rp^W^<l condtjclot ;in sen^i<x equipmeh^^

disconnecting means eng|dsure and the grounding electi'ode
systein. Each grounding electrode conductor shall be sized
in accordance with 250.66 based on the service-entrance
conductor(s) supplying the individual service disconnecting
tneans.

(3) Common Locaf Ion, A grounding electrode cohdu^
shall be connected tp, the gi'ounded service cohductor(s) in
;awireway or other accessible, enclosure on the supply sidej
of the service disconnecting means. The comiection shall
be made with exothermic welding or a connector listed as
grounding and bonding equipment. The grounding
electrode conductor shall be sized in accordance with
250.66 based on the service-entrance conductor's) at the
common location wter| the connection iS; made J

(E) Enclosures for Grounding Electrode Conductors.

Ferrous metal enclosures for grounding electrode conductors
shall be electrically continuous from the point of attachment to
cabinets or equipment to the grounding electrode and shall be
securely fastened to the ground clamp or fitting. Nonferrous
metal enclosures shall not be required to be electrically
continuous. Ferrous metal enclosures that are not physically
continuous from cabinet or equipment to the grounding
electrode shall be made electrically continuous by bonding
each end of the raceway or enclosure to the grounding
electrode conductor. Bonding shall apply at each end and to all
intervening ferrous raceways, boxes, and enclosures between
the cabinets or equipment and the grounding electrode. The
bonding jumper for a grounding electrode conductor raceway
or cable armor shall be the same size as, or larger than, the
enclosed grounding electrode conductor. Where a raceway is
used as protection for a grounding electrode conductor, the
installation shall comply with the requirements of the
appropriate raceway article.

(F) Installation to Electrode(s). Grounding electrode
conductor(s) and ; bonding jumpers . interconnecting
igrounding electrode^ shall be installed in accordance wiii

(1), (2), or (3). The grounding electrode conductor shall be
sized for the largest grounding electrode conductor
required among all the electrodes connected to it.

2010 California Electrical Code

70-107

250.66

ARTICLE 250 - GROUNDING AND BONDING

( 1 ) the grouniding ekptrode conductor shajl be; permitted

io! be run to any convenient grounding electrode
available in the grounding electrode system where the
other electrode(s), iif ariy^ are cqimecti^^ iby bonding
lumpers per! 250:^(^(2)5

(2) prouoding Jlectrade to'
jbe nin to one or more grounding electrode(s)
individually.

(3) Bonding jumpef(s) from grouadiiag eiectrpde(s) shall
J)e permitted to be connected p an aluminuini or copper
busbar not less than 6 mni >^ iO nnti i(3^ m^^^^ 2jjti.);
the busbar shall, he: sec;i:i^ly;&s^cin^ be
installed in an accessibk locatida Giabtiections shall;
be made, by a iistedf ci^hnbctor 6r: bj^jf &

.welding process,- the; grounding el&trpde: conductor
shall be permitted to be rim to the busbar, Wherei
aluminum bu$bar$ are used, the mstallation ^ha!l
jcoinply witii 250.64(A).

250.66 Size of Alternating-Current Grounding
Electrode Conductor. The size of the grounding electrode
conductor ai the service, at; 6aph;buiiding wherej

kippiied by a feed^r(s)J:<ir to

separately derived System of a grounded or ungrounded ac
system shall not be less than given in Table 250.66, except
as permitted in 250.66(A) through (C).

FPN: See 250.24(C) for size of ac system conductor
brought to service equipment.

(A) Connections to Rod, Pipe, or Plate Electrodes.

Where the grounding electrode conductor is connected to
rod, pipe, or plate electrodes as permitted in 250.52(A)(5)
or (A)(7), that portion of the conductor that is the sole
connection to the grounding electrode shall not be required
to be larger than 6 AWG copper wire or 4 AWG aluminum
wire.

(B) Connections to Concrete-Encased Electrodes. Where
the grounding electrode conductor is connected to a
concrete-encased electrode as permitted in 250.52(A)(3),
that portion of the conductor that is the sole connection to
the grounding electrode shall not be required to be larger
than 4 AWG copper wire.

(C) Connections to Ground Rings. Where the grounding
electrode conductor is connected to a ground ring as
permitted in 250.52(A)(4), that portion of the conductor
that is the sole connection to the grounding electrode shall
not be required to be larger than the conductor used for the
ground ring.

250.68 Grounding Electrode Conductor and Bonding
Jumper Connection to Grounding Electrodes, the

connection of a groundiiig electrode conductor- at thd
service, at each building; or sthicture ^vhere:^^ by a
ieederfs) or Ijr^ich circuil^s); or ial, a : Separately d^iyed
System and associated bonding jumper(s)jshaj be:n^^ as!

l^ofiedjZSOj^^ ^ ""^"'^ ' ' """" '"

Table 250.66 Grounding Electrode Conductor for
Alternating-Current Systems

Size of Largest Ungrounded

Service-Entrance Conductor or

Equivalent Area for Parallel

Conductorsa (AWG/kcmil)

Aluminum or

Copper-Clad

Aluminum

Size of Grounding

Electrode Conductor

(AWG/kcmil)

Aluminum
or Copper-
Clad

Copper

Aluminum**

2 or smaller

1/0 or smaller

1 or 1/0

2/0 or 3/0

4/0 or 250

Over 3/0 through
350

Over 250
through 500

1/0

Over 350
through 600

Over 500
through 900

1/0

3/0

Over 600
through 1100

Over 900
through 1750

2/0

4/0

Over 1100

Over 1750

3/0

250

Notes:

1 . Where multiple sets of service-entrance conductors are used as
permitted in 230.40, Exception No. 2, the equivalent size of the
largest service-entrance conductor shall be determined by the
largest sum of the areas of the corresponding conductors of each
set.

2. Where there are no service-entrance conductors, the grounding
electrode conductor size shall be determined by the equivalent
size of the largest service-entrance conductor required for the load
to be served.

aThis table also applies to the derived conductors of separately
derived ac systems.

bSee installation restrictions in 250.64(A).

(A) Accessibility. ^;^ me^^amcal ._ -^M^mk^^i}^^ \to
leiminate d grounding electrode conductor or bonding
jumper to a grounding electrode shall be accessible.

Exception No. 1: An encased or buried connection to a
concrete-encased, driven, or buried grounding electrode
shall not be required to be accessible.

Exception No. 2: "^Expthermic^or if^reyersi£lejobm^^
'connections used qt\ terntinations, together with the
mechanical means uleS to attach such terminations to
fjreproofed structural metal whether or not the mechanical
means is reversible, shhllnot be required to be accessible.

(B) Effective Grounding Path. The connection of a
grounding electrode conductor or bonding jumper to a
grounding electrode shall be made in a manner that will
ensure an effective grounding path. Where necessary to

70-108

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.92

ensure the grounding path for a metal piping system used
as a grounding electrode, bonding shall be provided
around insulated joints and around any equipment likely
to be disconnected for repairs or replacement. Bonding
jumpers- shall be of sufficient length to permit removal
of such equipment while retaining the integrity of the

250.70 Methods of Grounding and Bonding Conductor
Connection to Electrodes. The grounding or bonding
conductor shall be connected to the grounding electrode by
exothermic welding, listed lugs, listed pressure connectors,
listed clamps, or other listed means. Connections
depending on solder shall not be used. Ground clamps shall
be Hsted for the materials of the grounding electrode and
the grounding electrode conductor and, where used on pipe,
rod, or other buried electrodes, shall also be Hsted for direct
soil burial or concrete encasement. Not more than one
conductor shall be connected to the grounding electrode by
a single clamp or fitting unless the clamp or fitting is Hsted
for multiple conductors. One of the following methods
shall be used:

(1) A pipe fitting, pipe plug, or other approved device
screwed into a pipe or pipe fitting

(2) A listed bolted clamp of cast bronze or brass, or plain
or malleable iron

(3) For indoor telecommunications purposes only, a listed
sheet metal strap-type ground clamp having a rigid
metal base that seats on the electrode and having a
strap of such material and dimensions that it is not
likely to stretch during or after installation

(4) An equally substantial approved means

IV. Enclosure, Raceway, and Service Cable
Conii;|eetioiis

250.80 Service Raceways and Enclosures. Metal
enclosures and raceways for service conductors and
equipment shall be ^connected; to the grouaded systetri

ppriductbr!
groiftKiin^

if the electrical system is grdunded or to the
elec trcjde conductor for electrical systems Jlia^

Exception: A metal elbow that is installed in an
underground installation of rigid nonmetallic conduit and
is isolated from possible contact by a minimum cover of
450 mm (18 Ifl-Jjojony part of the elbow shall not be
required to be, connected to the grounded system conductor
pr gyggni&g electrode conductor,^

250.84 Underground Service Cable or Raceway.

(A) Underground Service Cable. The sheath or armor of a
continuous underground metal-sheathed or armored service
cable system that is connected to the grounded system
ccmdudbr^iOT side shall not be required to be

iconneptea taAe grounded sy stern conductor at the building
or structure. The sheath or armor shall be permitted to be
insulated from the interior metal raceway or piping.

(B) Underground Service Raceway Containing Cable.

An underground metal service raceway that contains a
metal-sheathed or armored cable |cgii|||;j| to the grounded
system iDonductot shall not be required to be connectedftp
the grounded system conductor at the building or structure.
The sheath or armor shall be permitted to be insulated from
the interior metal raceway or piping.

250.86 Other Conductor Enclosures and Raceways.

Except as permitted by 250.112(1), metal enclosures and
raceways for other than service conductors shall be
conaected to the eguipm^ grounding conductor.

Exception No. I: Metal enclosures and raceways for
conductors added to existing installations of open wire,
knob-and-tube wiring, and nonmetallic-sheathed cable
shall not be required to be connected to the equipment
grounding coHductor where these enclosures or wiring
methods comply with (1) through (4) as follows:

(1) Do not provide an equipment ground

(2) Are in runs of less than 7.5 m (25 ft)

(3) Are free from probable contact with ground,
grounded metal, metal lath, or other conductive material

(4) Are guarded against contact by persons

Exception No. 2: Short sections of metal enclosures or
raceways used to provide support or protection of cable
assemblies from physical damage shall not be required to
be connected to the equipment grounding conductor:

Exception No. 3: A metal elbow shall not be required to be
connected to the equipment grounding conductor where it
is installed in a nonmetallic raceway and is isolated from
possible contact by a minimum cover of 450 mm (18 in.) to
any part of the elbow or is encased in not less than 50 mm
(2 in.) of concrete.

V. Bonding

250.90 General. Bonding shall be provided where
necessary to ensure electrical continuity and the capacity to
conduct safely any fault current Hkely to be imposed.

250.92 Services.

(A) Bonding of Services. The non-current-carrying metal
parts of equipment indicated in 250.92(A)|B^^^S|iii
shall be bonded together.

(1) The service raceways, cable trays, cablebus framework,
auxiliary gutters, or service cable armor or sheath except
as permitted in 250.84

(2) All service enclosures containing service conductors,
including meter fittings, boxes, or the like, interposed
in the service raceway or armor

2010 California Electrical Code

70---109

250.94

ARTICLE 250 - GROUNDING AND BONDING

(B) Method of Bonding at the Service. Electrical
continuity at service equipment, service raceways, and
service conductor enclosures shall be ensured by one of the
following methods:

(1) Bonding equipment to the grounded service conductor
in a manner provided in 250.8

(2) Connections utilizing threaded couplings or threaded
bosses on enclosures where made up wrenchtight

(3) Threadless couplings and connectors where made up
tight for metal raceways and metal-clad cables

(4) Other hsted devices, such as bonding-type locknuts,
bushings, or bushings with bonding jumpers

Bonding jumpers meeting the other requirements of this
article shall be used around concentric or eccentric
knockouts that are punched or otherwise formed so as to
impair the electrical connection to ground. Standard
locknuts or bushings shall not be the sole means for the
bonding required by this section.

250.94 Bonding for Other Systems. An intarsystem
bonding termidation for coimecting; intersystem bonding
and grounding conductors; requited for; other systems shall
be provided externaLt6;ebclQSures;at the service eguipineint
and atthe discomiecting hieans^for any additional buildings,
or stmctures; ; Jhf :mM^^ bonding termination shall be

accessible iotconmctipn. and inspection, The intersystem
bonding teriBiniatiohshiail have the capacity for connection
of not less than three ititersystem bonding conductors. The
intersystem bonding tehriination device shall not interfere
with opening a service or metering equipment enclosure.
The intersystem bonding terrnination shall be one of the
following:

( 1 ) A set of terminals Securely mounted to the meter
enotosnre and electrically connected to the meter
eiicldsure. the terminals shall be listed as groundixig
and bonding equipment.

(2) A bonding ; bar iiea^th^ service equipment enclosure,;
meter enclosure, or raceway for service conductors.;
:The bonding; bar shah be connected with a minimum 6
AWG copper cdndUctdr to an equipment grounding
cpnductor(s) in the service equipment enclosure^ rnetei;
encloswe, or exposed nqnfle^^^^

(3) Aborting bar near ;&

J>onding bar sh^U be^Gpmi^ to tlie grounding electrode
ponductor wth a ;i|^

Exception: iwexisUhg biiilcimgs Or structures where any of
the intersystem : bondirig and grounding conductors
requkeffy -mM'SOamfy^ 810:2 1(F), 820J00(BX
830 J 00(B) exist, installation of th& intersystem bonding
termination 'is}not reguired^ An accessible means external
to enclosures for connecting intersystem bonding and
grounding electrode conductors shall be perrnitted at the

service equipment and at the disconnecting means for any
additional buildings or structures by at least one of the
following means:

(1) Exposed nonflexible metallic raceways

(2) An exposed grounding electrode conductor

(3) Approved means for the external connection of a
copper or other corrosion-resistant bonding or grounding
conductor to the grounded raceway or equipment

FPN No. 1: A 6 AWG copper conductor with one end
bonded to the grounded nonflexible metalhc raceway or
equipment and with 150 mm (6 in.) or more of the other end
made accessible on the outside wall is an example of the
approved means covered in 250.94, Exceptiotiitem (3).

FPN No. 2: See 800.100, 810.21, and 820.100 for bonding
and grounding requirements for communications circuits,
radio and television equipment, and CATV circuits.

250.96 Bonding Other Enclosures.

(A) General. Metal raceways, cable trays, cable armor,
cable sheath, enclosures, frames, fittings, and other metal
non-current-carrying parts that are to serve as grounding
conductors, with or without the use of supplementary
equipment grounding conductors, shall be bonded where
necessary to ensure electrical continuity and the capacity to
conduct safely any fault current likely to be imposed on
them. Any nonconductive paint, enamel, or similar coating
shall be removed at threads, contact points, and contact
surfaces or be connected by means of fittings designed so
as to make such removal unnecessary.

(B) Isolated Grounding Circuits. Where installed for the
reduction of electrical noise (electromagnetic interference)
on the grounding circuit, an equipment enclosure supplied
by a branch circuit shall be permitted to be isolated from a
raceway containing circuits supplying only that equipment
by one or more listed nonmetallic raceway fittings located
at the point of attachment of the raceway to the equipment
enclosure. The metal raceway shall comply with provisions
of this article and shall be supplemented by an internal
insulated equipment grounding conductor installed in
accordance with 250.146(D) to ground the equipment
enclosure.

FPN: Use of an isolated equipment grounding conductor
does not relieve the requirement for grounding the raceway
system.

250.97 Bonding for Over 250 Volts. For circuits of over
250 vohs to ground, the electrical continuity of metal
raceways and cables with metal sheaths that contain any
conductor other than service conductors shall be ensured by
one or more of the methods specified for services in
250.92(B), except for (B)(1).

Exception: Where oversized, concentric, or eccentric
knockouts are not encountered, or where a box or
enclosure with concentric or eccentric knockouts is listed
to provide a reliable pondmg connection, the following
methods shall be permitted:

70-110

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.104

(1) Threadless couplings and connectors for cables
with metal sheaths

(2) Two locknuts, on rigid metal conduit or
intermediate metal conduit, one inside and one outside of
boxes and cabinets

(3) Fittings with shoulders that seat firmly against the
box or cabinet, such as electrical metallic tubing
connectors, flexible metal conduit connectors, and cable
connectors, with one locknut on the inside of boxes and
cabinets

(4) Listed fittings

250.98 Bonding Loosely Jointed Metal Raceways.

Expansion fittings and telescoping sections of metal
raceways shall be made electrically continuous by
equipment bonding jumpers or other means.

250.100 Bonding in Hazardous (Classified) Locations.

Regardless of the voltage of the electrical system, the
electrical continuity of non-current-carrying metal parts of
equipment, raceways, and other enclosures in any
hazardous (classified) location as defined in ^^^^ shall be
ensured by any of the boriding methods specified in
250.92(B)(2) through (B)(4). One or more of these bonding
methods shall be used whether or not equipment grounding
conductors §5ffla wfre|yp§ are installed.

250.102 Equipment Bonding Jumpers.

(A) Material. Equipment bonding jumpers shall be of
copper or other corrosion-resistant material. A bonding
jumper shall be a wire, bus, screw, or similar suitable
conductor.

(B) Attachment. Equipment bonding jumpers shall be
attached in the manner specified by the applicable
provisions of 250.8 for circuits and equipment and by
250.70 for grounding electrodes.

(C) Size — Equipment Bonding Jumper on Supply Side
of Service. The bonding jumper shall not be smaller than
the sizes shown in Table 250.66 for grounding electrode
conductors. Where the service-entrance phase conductors
are larger than 1 100 kcmil copper or 1750 kcmil aluminum,
the bonding jumper shall have an area not less than 12!/2
percent of the area of the largest phase conductor except
that, where the phase conductors and the bonding jumper
are of different materials (copper or aluminum), the
minimum size of the bonding jumper shall be based on the
assumed use of phase conductors of the same material as
the bonding jumper and with an ampacity equivalent to that
of the installed phase conductors. Where the service-
entrance conductors are paralleled in two or more raceways
or cables, the equipment bonding jumper, where routed

with the raceways or cables, shall be run in parallel. The
size of the bonding jumper for each raceway or cable shall
be based on the size of the service-entrance conductors in
each raceway or cable.

(D) Size — Equipment Bonding Jumper on Load Side
of Service. The equipment bonding jumper on the load side
of the service overcurrent devices shall be sized, as a
minimum, in accordance with the sizes listed in Table
250.122, but shall not be required to be larger than the
largest ungrounded circuit conductors supplying the
equipment and shall not be smaller than 14 AWG.

A single common continuous equipment bonding
jumper shall be permitted to connect two or more raceways
or cables where the bonding jumper is sized in accordance
with Table 250.122 for the largest overcurrent device
supplying circuits therein.

(E) Installation. The equipment bonding jumper shall
be permitted to be installed inside or outside of a
raceway or enclosure. Where installed on the outside,
the length of the equipment bonding jumper shall not
exceed 1.8 m (6 ft) and shall be routed with the raceway
or enclosure. Where installed inside a raceway, the
equipment bonding jumper shall comply with the
requirements of 250.119 and 250.148.

Exception: An equipment bonding jumper longer than 1.8
m (6 ft) shall be permitted at outside pole locations for the
purpose of bonding or grounding isolated sections of metal
raceways or elbows installed in exposed risers of metal
conduit or other metal raceway,

250.104 Bonding of Piping Systems and Exposed
Structural Steel.

(A) Metal Water Piping. The metal water piping system
shall be bonded as required in (A)(1), (A)(2), or (A)(3) of
this section. The bonding jumper(s) shall be installed in
accordance with 250.64(A), (B), and (E). The points of
attachment of the bonding jumper(s) shall be accessible.

(1) General. Metal water piping system(s) installed in or
attached to a building or structure shall be bonded to the
service equipment enclosure, the grounded conductor at the
service, the grounding electrode conductor where of
sufficient size, or to the one or more grounding electrodes
used. The bonding jumper(s) shall be sized in accordance
with Table 250.66 except as permitted in 250.104(A)(2)
and (A)(3).

(2) Buildings of Multiple Occupancy. In buildings of
multiple occupancy where the metal water piping system(s)
installed in or attached to a building or structure for the
individual occupancies is metallically isolated from all

2010 California Electrical Code

70-111

250.104

ARTICLE 250 - GROUNDING AND BONDING

Other occupancies by use of nonmetallic water piping, the
metal water piping system(s) for each occupancy shall be
permitted to be bonded to the equipment grounding
terminal of the panelboard or switchboard enclosure (other
than service equipment) supplying that occupancy. The
bonding jumper shall be sized in accordance with Table
250.122, based on the rating of the overcurretit protective
;device for thC; circuit supplying the occupaiicy.

(3) Multiple Buildings or Structures Supplied by a
Feeder(s) or Branch Circuit(s). The metal water piping
system(s) installed in or attached to a building or structure
shall be bonded to the building or structure disconnecting
means enclosure where located at the building or structure,
to the equipment grounding conductor run with the supply
conductors, or to the one or more grounding electrodes
used. The bonding jumper(s) shall be sized in accordance
with 250.66, based on the size of the feeder or branch
circuit conductors that supply the building. The bonding
jumper shall not be required to be larger than the largest
ungrounded feeder or branch circuit conductor supplying
the building.

(B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure, the grounded
conductor at the service, the grounding electrode conductor
where of sufficient size, or the one or more grounding
electrodes used. The bonding jumper(s) shall be sized in
accordance with 250.122, using the rating of the circuit that
is likely to energize the piping system(s). The equipment
grounding conductor for the circuit that is likely to energize
the piping shall be permitted to serve as the bonding
means. The points of attachment of the bonding jumper(s)
shall be accessible.

FPN: Bonding all piping and metal air ducts within the
premises will provide additional safety.

(C) Structural Metal. Exposed structural metal that is
interconnected to form a metal building frame and is not
intentionally grounded and is likely to become energized
shall be bonded to the service equipment enclosure, the
grounded conductor at the service, the grounding electrode
conductor where of sufficient size, or the one or more
grounding electrodes used. The bonding jumper(s) shall be
sized in accordance with Table 250.66 and installed in
accordance with 250.64(A), (B), and (E). The points of
attachment of the bonding jumper(s) shall be accessible.

(D) Separately Derived Systems. Metal water piping
systems and structural metal that is interconnected to form
a building frame shall be bonded to separately derived
systems in accordance with (D)(1) through (D)(3).

(1) Metal Water Piping System(s). The grounded
conductor of each separately derived system shall be
bonded to the nearest available point of the metal water
piping system(s) in the area served by each separately
derived system. This connection shall be made at the same
point on the separately derived system where the grounding
electrode conductor is connected. Each bonding jumper
shall be sized in accordance with Table 250.66 based on
the largest ungrounded conductor of the separately derived
system.

Exception No. 1: A separate bonding jumper to the metal
water piping system shall not be required where the metal
water piping system is used as the grounding electrode for
the separately derived 'system and the water pipm^^^
is in the area served^

. Exception No. 2: A separate water piping bonding jumper
shall not be required where the metal frame of a building
or structure is used as the grounding electrode for a
separately derived system and is bonded to the metal water
piping in the area served by the separately derived system.

(2) Structural Metal. Where exposed structural metal that
is interconnected to form the building frame exists in the
area served by the separately derived system, it shall be
bonded to the grounded conductor of each separately derived
system. This connection shall be made at the same point on
the separately derived system where the grounding electrode
conductor is connected. Each bonding jumper shall be sized
in accordance with Table 250.66 based on the largest
ungrounded conductor of the separately derived system.

Exception No. 1: A separate bonding jumper to the
building structural metal shall not be required where the
metal frame of a building or structure is used as the
grounding electrode for the separately derived system.

Exception No. 2: A separate bonding jumper to the
building structural metal shall not be required where the
water piping of a building or structure is used as the
grounding electrode for a separately derived system and is
bonded to the building structural metal in the area served
by the separately derived system.

(3) Common Grounding Electrode Conductor. Where a
common grounding electrode conductor is installed for
multiple separately derived systems as permitted by
250.30(A)(4), and exposed structural metal that is
interconnected to form the building frame or interior metal
piping exists in the area served by the separately derived
system, the metal piping and the structural metal member
shall be bonded to the common grounding electrode
conductor.

Exception: A separate bonding jumper from each derived
system to metal water piping and to structural metal
members shall not be required where the metal water
piping and the structural metal members in the area served
by the separately derived system are bonded to the common
grounding electrode conductor.

70-112

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.112

250.106 Lightning Protection Systems. The lightning
protection system ground terminals shall be bonded to the
building or structure grounding electrode system.

FPN No. 1: See 250.60 for use of air terminals. For further
information, see NFPA 780-2008, Standard for the
Installation of Lightning Protection Systems, which contains
detailed information on grounding, bonding, and sideflash
distance from lightning protection systems.

FPN No. 2: Metal raceways, enclosures, frames, and other
non-current-carrying metal parts of electrical equipment
installed on a building equipped with a lightning protection
system may require bonding or spacing from the lightning
protection conductors in accordance with NFPA 780-2008,
Standard for the Installation of Lightning Protection
Systems.

VI. Equipment Grounding and Equipment Grounding
Conductors

250.110 Equipment Fastened in Place or Connected by
Permanent Wiring Methods (Fixed).

Exposed non-current-carrying metal parts of fixed
equipment likely to become energized shall be Ooiinacted to
ithe equipment grounding conductor under any of the
following conditions:

(1) Where within 2.5 m (8 ft) vertically or 1.5 m (5 ft)
horizontally of ground or grounded metal objects and
subject to contact by persons

(2) Where located in a wet or damp location and not
isolated

(3) Where in electrical contact with metal

(4) Where in a hazardous (classified) location as covered
by Articles 500 through 517

(5) Where supplied by a metal-clad, metal-sheathed,
metal-raceway, or other wiring method that provides
an equipment ground, except as permitted by 250.86,
Exception No. 2, for short sections of metal enclosures

(6) Where equipment operates with any terminal at over
150 volts to ground

Exception No. I: Metal frames of electrically heated
appliances, exempted by special permission, in which case
the frames shall be permanently and effectively insulated
from ground.

Exception No. 2: Distribution apparatus, such as
transformer and capacitor cases, mounted on wooden
poles, at a height exceeding 2.5 m (8 ft) above ground or
grade level.

Exception No. 3: Listed equipment protected by a system
of double insulation, or its equivalent, shall not be required

to be [.corin^edj^ equipment^^grMndmg, C0§di^t0n
Where such a system is employed, the equipment shall be
distinctively marked.

250.112 Fastened in Place or Connected by Permanent
Wiring Methods (Fixed) — Specific. Except as permitted

in 250. 1 12(I)jf exposed, non-current-carrying metal parts of
the kinds of equipment described in 250.112(A) through
(K), and non-current-carrying metal parts of equipment
and enclosures described in 250.1I2(L) and (M), |>haU be
corinected to: the equipmert^^ coiiduttpr regardless

of voltage.

(A) Switchboard Frames and Structures. Switchboard
frames and structures supporting switching equipment,
except frames of 2-wire dc switchboards where effectively
insulated from ground.

(B) Pipe Organs. Generator and motor frames in an
electrically operated pipe organ, unless effectively
insulated from ground and the motor driving it.

(D) Enclosures for Motor Controllers. Enclosures for
motor controllers unless attached to ungrounded portable
equipment.

(E) Elevators and Cranes. Electrical equipment for
elevators and cranes.

(F) Garages, Theaters, and Motion Picture Studios.

Electrical equipment in commercial garages, theaters, and
motion picture studios, except pendant lampholders
supplied by circuits not over 150 volts to ground.

(G) Electric Signs. Electric signs, outline lighting, and
associated equipment as provided in 600.7.

(H) Motion Picture Projection Equipment. Motion
picture projection equipment.

(I) Remote-Control, Signaling, and Fire Alarm Circuits.

EquipmeS:suppiied by Class: 1 circuits shall te grounded
imi^ss operating at fe^^ Equipment supplied

by Class 1 power-limited circuits, by Class 2 and Class 3
remote-control and signaling circuits, and by fire alarm
circuits shall be grounded where system grounding is
required by Part II or Part VIII of this article.

(J) Luminaires. Luminaires as provided in Part V of
Article 410,

(K) Skid-Mounted Equipment. Permanently mounted
electrical equipment and skids shall be P^^^^^^^^^jM'M^
equipment grounding conductqi! sized as required by

250.122.

(L) Motor-Operated Water Pumps. Motor-operated
water pumps, including the submersible type.

(M) Metal Well Casings. Where a submersible pump is used
in a metal well casing, the well casing shall be connected to
the pump circuit equipment grounding conductor.

2010 California Electrical Code

70-113

250.114

ARTICLE 250 - GROUNDING AND BONDING

250.114 Equipment Connected by Cord and Plug.

Under any of the conditions described in 250.114(1)
through (4), exposed non-current-carrying metal parts of
cord-and-plug-connected equipment likely to become
energized shall be ^^onnected to the equipment groimding
iDondactor.

Exception: Listed tools, listed appliances, and listed
equipment covered in 250.114(2) through (4) shall not be
required to he connected to an equipment grounding
conductor where protected by a system of double insulation
or its equivalent. Double insulated equipment shall be
distinctively marked,

(1) In hazardous (classified) locations (see Articles 500
through 517)

(2) Where operated at over 150 volts to ground
Exception No. 1: Motors, where guarded, shall npl be
required to be connected to an equipment g^oujfding
conductor.

Exception No. 2: Metal frames of electrically heated
appliances, exempted by special permission, shall not be
required to be connected to an equipment grounding
conductor; in which case the frames shall be permanently
and effectively insulated from ground.
I (3) In residential occupancies:

a. Refrigerators, freezers, and air conditioners

b. Clothes-washing, clothes-drying, dish-washing
machines; kitchen waste disposers; information
technology equipment; sump pumps and electrical
aquarium equipment

c. Hand-held motor-operated tools, stationary and
fixed motor-operated tools, and light industrial
motor-operated tools

d. Motor-operated appliances of the following types:
hedge clippers, lawn mowers, snow blowers, and
wet scrubbers

e. Portable handlamps

(4) In other than residential occupancies:

a. Refrigerators, freezers, and air conditioners

b. Clothes-washing, clothes-drying, dish- washing
machines; information technology equipment;
sump pumps and electrical aquarium equipment

c. Hand-held motor-operated tools, stationary and
fixed motor-operated tools, and light industrial
motor-operated tools

d. Motor-operated appliances of the following types:
hedge clippers, lawn mowers, snow blowers, and
wet scrubbers

e. Portable handlamps

f. Cord-and-plug-connected appliances used in damp

or wet locations or by persons standing on the
ground or on metal floors or working inside of
metal tanks or boilers

g. Tools likely to be used in wet or conductive
locations

Exception: Tools and portable handlamps likely to be used
in wet or conductive locations shall not be required to be
connected '■jq :M e^ <^P^4MPi where

supplied through an isolating transformer with an
ungrounded secondary of not over 50 volts.

250.116 Nonelectrical Equipment. The metal parts of the
following nonelectrical equipment described in this section
shall be connected to the equij)m^iit grpuhding conductqg

(1) Frames and tracks of electrically operated cranes and
hoists

(2) Frames of nonelectrically driven elevator cars to which
electrical conductors are attached

(3) Hand-operated metal shifting ropes or cables of electric
elevators

FPN: Where extensive metal in or on buildings may become
energized and is subject to personal contact, adequate
bonding and grounding will provide additional safety.

250.118 Types of Equipment Grounding Conductors.

The equipment grounding conductor run with or enclosing
the circuit conductors shall be one or more or a
combination of the following:

FBN:''For :;effeetiye':|rouiid-fa^^ path,; see; 250.2

DefinitJQni

(1) A copper, aluminum, or copper-clad aluminum
conductor. This conductor shall be solid or stranded;
insulated, covered, or bare; and in the form of a wire or
a busbar of any shape.

(2) Rigid metal conduit.

(3) Intermediate metal conduit.

(4) Electrical metallic tubing.

(5) Listed flexible metal conduit meeting all the following
conditions:

a. The conduit is terminated m listed fittings.

b. The circuit conductors contained in the conduit are

protected by overcurrent devices rated at 20
amperes or less.

c. The combined length of flexible metal conduit and

flexible metallic tubing and liquidtight flexible
metal conduit in the same ground return path does
not exceed 1.8 m (6 ft).

d. Where used to connect equipment where flexibility

is necessary after installation, an equipment
grounding conductor shall be installed.

(6) Listed liquidtight flexible metal conduit meeting all the
following conditions:

a. The conduit is terminated in listed fittings.

b. For metric designators 12 through 16 (trade sizes

3/8 through V2), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated at 20 amperes or less.

•

70-114

2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250,120

c. For metric designators 21 through 35 (trade sizes Va

through 1%), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated not more than 60 amperes and there is no
flexible metal conduit, flexible metallic tubing, or
liquidtight flexible metal conduit in trade sizes
metric designators 12 through 16 (trade sizes 3/8
through V2) in the grounding path.

d. The combined length of flexible metal conduit and

flexible metallic tubing and liquidtight flexible
metal conduit in the same ground return path does
not exceed 1 .8 m (6 ft).

e. Where used to connect equipment where flexibility

is necessary after installation, an equipment
grounding conductor shall be installed.

(7) Flexible metallic tubing where the tubing is terminated
in Usted fitiiBg§ and meeting the following conditions:

a. The circuit conductors contained in the tubing are

protected by overcurrent devices rated at 20
amperes or less.

b. The combined length of flexible metal conduit and

flexible metallic tubing and liquidtight flexible
metal conduit in the same ground return path does
not exceed 1.8 m (6 ft).

(8) Armor of Type AC cable as provided in 320. 108.

(9) The copper sheath of mineral-insulated, metal-sheathed
cable.

(10) Type MC cable where listed and identified for
grounding in accordance with the following:

a. The combined metallic sheath and grounding

conductor of interlocked metal tape-type MC cable

b. The metallic sheath or the combined metallic sheath

and grounding conductors of the smooth or
corrugated tube-type MC cable

(11) Cable trays as permitted in 392.3 and 392.7.

(12) Cablebus framework as permitted in 370.3.

(13) Other listed electrically continuous metal raceways
and listed auxiliary gutters.

(14) Surface metal raceways listed for grounding.

250.119 Identification of Equipment Grounding
Conductors. Unless required elsewhere in this Code,
equipment grounding conductors shall be permitted to be
bare, covered, or insulated. Individually covered or
insulated equipment grounding conductors shall have a
continuous outer finish that is either green or green with
one or more yellow stripes except as permitted in this
section. Conductors with insulation or individual covering
that is green, green with one or more yellow stripes, or
otherwise identified as permitted by this section shall not
be used for ungrounded or grounded circuit conductors.

Exception: Ppwer-Umited, Class :2 or Class 3 circuit
cables containing only circuits operating less than 50
yolts shall be pernntted to use. a cpnditctor mth green
insulation for other than equipment grotindihg purposes:

(A) Conductors Larger Than 6 AWG. Equipment
grounding conductors larger than 6 AWG shall comply
with 250.1 19(A)(1) and (A)(2).

(1) An insulated or covered conductor larger than 6 AWG
shall be permitted, at the time of installation, to be
permanently identified as an equipment grounding
conductor at each end and at every point where the
conductor is accessible.

Exception: Conductors larger than 6 A WG shall not be
required to be marked in conduit bodies that contain no
splices or unused hubs.

(2) Identification shall encircle the conductor and shall be
accomplished by one of the following:

a. Stripping the insulation or covering from the entire
exposed length

b. Coloring the insulation or covering green at the
tej;rnin^tidn

c. Marking the insulation or covering with green tape
or green adhesive labels jat the termmation

(B) Multiconductor Cable. Where the condifions of
maintenance and supervision ensure that only qualified
persons service the installation, one or more insulated
conductors in a multiconductor cable, at the time of
installation, shall be permitted to be permanently identified
as equipment grounding conductors at each end and at
every point where the conductors are accessible by one of
the following means:

(1) Stripping the insulation from the entire exposed length

(2) Coloring the exposed insulation green

(3) Marking the exposed insulation with green tape or
green adhesive labels

(C) Flexible Cord. An uninsulated equipment grounding
conductor shall be permitted, but, if individually covered,
the covering shall have a continuous outer finish that is
either green or green with one or more yellow stripes.

250.120 Equipment Grounding Conductor Installation.

An equipment grounding conductor shall be installed in
accordance with 250.120(A), (B), and (C).

(A) Raceway, Cable Trays, Cable Armor, Cablebus, or
Cable Sheaths. Where it consists of a raceway, cable txay,
cable armor, cablebus framework, or cable sheath or where
it is a wire within a raceway or cable, it shall be installed in
accordance with the applicable provisions in this Code
using fittings for joints and terminations approved for use
with the type raceway or cable used. All connections,
joints, and fittings shall be made tight using suitable tools.

2010 California Electrical Code

70-115

250.122

ARTICLE 250 - GROUNDING AND BONDING

FPN: See the UL gyidemfotmation on FHIT systems for
equipment groimdiag coBdtictors installed in a raceway that
aire patt of an el ectdcal circuit. protective systeni or a fire:i
irated cable listed to rnaintaih^(;:ircuit integrity.

(B) Aluminum and Copper-Clad Aluminum
Conductors. Equipment grounding conductors of bare or
insulated aluminum or copper-clad aluminum shall be
permitted. Bare conductors shall not come in direct contact
with masonry or the earth or where subject to corrosive
conditions. Aluminum or copper-clad aluminum
conductors shall not be terminated within 450 mm (18 in.)
of the earth.

AWG. Equipment grounding conductors smaller than 6
AWG shall be protected from physical damage by a
raceway or cable armor except where run in hollow spaces
of walls or partitions, where not subject to physical
damage, or where protected from physical damage.

250.122 Size of Equipment Grounding Conductors.

(A) General. Copper, aluminum, or copper-clad aluminum
equipment grounding conductors of the wire type shall not
be smaller than shown in Table 250.122, but in no case
shall they be required to be larger than the circuit
conductors supplying the equipment. Where a cable tray, a
raceway, or a cable armor or sheath is used as the
equipment grounding conductor, as provided in 250.118
and 250.134(A), it shall comply with 250.4(A)(5) or (B)(4).

(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately
according to the circular mil area of the ungrounded
conductors.

(C) Multiple Circuits. Where a single equipment
grounding conductor is run with multiple circuits in the
same raceway, cable, or pable tray,; it shall be sized for the
largest overcurrent device protecting conductors in the
raceway, cable, or cable tray. Equipment: groundiag
conductors installed in cable trays shall meet the miBimuni
requirements of 392.3(B)(1Xp)v

(D) Motor Circuits. Equipment grouading conducibfs for
motor Circuits shall be with (D)(1) or

|(3X /General. The equiprnent grpunding conductor size;
Ishail not be smaller than detennined by 250.122(A) based
ipn the rating of the branch-circuit short-circuit and ground-
iault protective device.

(2) I«stantaneous-Trip Circuit Breaker and Motor
Shorjt-Circuit Protector. Where the overcurrent device is
ah; instantanec^s4rip ;: circuit b^ or a motor ■■ short-
jcircuit protector, theleguipnientvg^^ conductqr shall

be :si2;ed hot smalter than that g^^^ by 250422(A;) iising
JtLeniaximumpermit^^^^ dual element time-delay

fuse selected ■ forhvmc^-ck(^s^

fault protectioiii : ; in : accordanqe;J^;wrffi C:^ 430i52(C)(l)^

Exception iSfovi.'

(E) Flexible Cord and Fixture Wire. The equipment
grounding conductor in a flexible cord with the largest
circuit conductor 10 AWG or smaller, and the equipment
grounding conductor used with fixture wires of any size in
accordance with 240.5, shall not be smaller than 18 AWG
copper and shall not be smaller than the circuit conductors.
The equipment grounding conductor in a flexible cord with
a circuit conductor larger than 10 AWG shall be sized in
accordance with Table 250. 122.

(F) Conductors in Parallel. Where conductors are run in
parallel in multiple raceways or cables as permitted in
310.4, the equipment grounding conductors, where used,
shall be run in parallel in each raceway or cable.

Each parallel equipment grounding conductor shall be
sized on the basis of the ampere rating of the overcurrent
device protecting the circuit conductors in the raceway or
cable in accordance with Table 250.122,

(G) Feeder Taps. Equipment grounding conductors run
with feeder taps shall not be smaller than shown in Table
250.122 based on the rating of the overcurrent device ahead
of the feeder but shall not be required to be larger than the
tap conductors.

250.124 Equipment Grounding Conductor Continuity.

(A) Separable Connections. Separable connections such
as those provided in drawout equipment or attachment
plugs and mating connectors and receptacles shall provide
for first-make, last-break of the equipment grounding
conductor. First-make, last-break shall not be required
where interlocked equipment, plugs, receptacles, and
connectors preclude energization without grounding
continuity.

(B) Switches. No automatic cutout or switch shall be
placed in the equipment grounding conductor of a premises
wiring system unless the opening of the cutout or switch
disconnects all sources of energy.

250.126 Identification of Wiring Device Terminals. The

terminal for the connection of the equipment grounding
conductor shall be identified by one of the following:

(1) A green, not readily removable terminal screw with a
hexagonal head.

(2) A green, hexagonal, not readily removable terminal nut.

(3) A green pressure wire cormector. If the terminal for the
grounding conductor is not visible, the conductor

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ARTICLE 250 - GROUNDING AND BONDING

250.134

Table 250.122 Minimum Size Equipment Grounding
Conductors for Grounding Raceway and Equipment

Size (AWG

or kcmil)

Rating or Setting of

Automatic Overcurrent

Device in Circuit Aliead of

Equipment, Conduit, etc.,

Not Exceeding (Amperes)

Copper

Aluminum or
Copper-Clad
Aluminum*

100

200

300

400

500

1/0

600

2/0

800

1/0

3/0

1000

2/0

4/0

1200

3/0

250

1600

4/0

350

2000

250

400

2500

350

600

3000

400

600

4000

500

800

5000

700

1200

6000

800

1200

Note: Where necessary to comply with 250.4(A)(5) or (B)(4), the

equipment grounding conductor shall be sized larger than given in

this table.

*See installation restrictions in 250.120.

entrance hole shall be marked with the word green or
ground, the letters G or GR, a grounding symbol, or
otherwise identified by a distinctive green color. If the
terminal for the equipment grounding conductor is
readily removable, the area adjacent to the terminal
shall be similarly marked.
FPN: See FPN Figure 250.126.

FPN Figure 250.126 One Example of a Symbol Used to
Identify the Grounding Termination Point for an
Equipment Grounding Conductor.

VII. Methods of Equipment Grounding

250.130 Equipment Grounding Conductor Connections.

Equipment grounding conductor connections at the source
of separately derived systems shall be made in accordance

with 250.30(A)(1). Equipment grounding conductor
connections at service equipment shall be made as
indicated in 250.130(A) or (B). For replacement of non-
grounding- type receptacles with grounding-type
receptacles and for branch-circuit extensions only in
existing installations that do not have an equipment
grounding conductor in the branch circuit, connections
shall be permitted as indicated in 250.130(C).

(A) For Grounded Systems. The connection shall be
made by bonding the equipment grounding conductor to
the grounded service conductor and the grounding
electrode conductor.

(B) For Ungrounded Systems. The connection shall be
made by bonding the equipment grounding conductor to
the grounding electrode conductor.

(C) Nongrounding Receptacle Replacement or Branch
Circuit Extensions. The equipment grounding conductor of
a grounding-type receptacle or a branch-circuit extension
shall be permitted to be connected to any of the following:

(1) Any accessible point on the grounding electrode
system as described in 250.50

(2) Any accessible point on the grounding electrode
conductor

(3) The equipment grounding terminal bar within the
enclosure where the branch circuit for the receptacle or
branch circuit originates

(4) For grounded systems, the grounded service conductor
within the service equipment enclosure

(5) For ungrounded systems, the grounding terminal bar
within the service equipment enclosure

FPN: See 406.3(D) for the use of a ground-fault circuit-
interrupting type of receptacle.

250.132 Short Sections of Raceway. Isolated sections of
metal raceway or cable armor, where required to be
grounded, shall be ponhmpd to to eqiiipinpnt grounding

coaducto| in accordance with 250.134.

250.134 Equipment Fastened in Place or Connected by
Permanent Wiring Methods (Fixed) — Grounding.

Unless grounded by connection to the grounded circuit
conductor as permitted by 250.32, 250.140, and 250.142,
non-current-carrying metal parts of equipment, raceways,
and other enclosures, if grounded, shall be bonnected tq^ari
equipment grou nding conductor by one of the methods
specified in 250.134(A) or (B).

(A) Equipment Grounding Conductor Types. By

^qnnecii|ig;.to: any of the equipment grounding conductors
permitted! by 250.1 18.

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250.136

ARTICLE 250 - GROUNDING AND BONDING

(B) With Circuit Conductors. By coimectitig to an

equipment grounding conductor contained within the same
raceway, cable, or otherwise run with the circuit conductors.

Exception No. 1: As provided in 2 50 J 30(C), the
equipment grounding conductor shall be permitted to be
run separately from the circuit conductors.

Exception No. 2: For dc circuits, the equipment grounding
conductor shall be permitted to be run separately from the
circuit conductors.

FPN No. 1: See 250.102 and 250.168 for equipment
bonding jumper requirements.

FPN No. 2: See 400.7 for use of cords for fixed equipment.

250.136 Equipment Considered Grounded. Under the
conditions specified in 250.136(A) and (B), the nprmallj^
non-current-carrying metal parts of the equipment shall be
considered grounded.

(A) Equipment Secured to Grounded Metal Supports.

Electrical equipment secured to and in electrical contact
with a metal rack or structure provided for its support and
connected to an equipment grounding condxiotor by one of
the means indicated in 250.134. The structural metal frame
of a building shall not be used as the required equipment
grounding conductor for ac equipment.

(B) Metal Car Frames, Metal car frames supported by
metal hoisting cables attached to or running over metal
sheaves or drums of elevator machines that are connected
to an eijuipmetit grounding conduc^^ by one of the
methods indicated in 250.134.

250.138 Cord-and-Plug-Connected Equipment. Non-
current-carrying metal parts of cord-and-plug-connected
equipment, if grounded, shall be cbmiected to an equipment
grounding conductor by one of the methods in 250.138(A)
or(B).

(A) By Means of an Equipment Grounding Conductor.

By means of an equipment grounding conductor run with
the power supply conductors in a cable assembly or
flexible cord properly terminated in a grounding-type
attachment plug with one fixed grounding contact.

Exception: The grounding contacting pole of grounding-
type plug-in ground-fault circuit interrupters shall be
permitted to be of the movable, self-restoring type on
circuits operating at not over 150 volts between any two
conductors or over 150 volts between any conductor and
ground.

(B) By Means of a Separate Flexible Wire or Strap, By

means of a separate flexible wire or strap, insulated or bare,
connected to an equipment groxinding condijctor^- and

protected as well as practicable against physical damage,
where part of equipment.

250.140 Frames of Ranges and Clothes Dryers. Frames
of electric ranges, wall-mounted ovens, counter-mounted
cooking units, clothes dryers, and outlet or junction boxes
that are part of the circuit for these appliances shall be
jc6mec|e&to;rh in the

manner specifiedTy 25a

Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the outlet or junction box, the frames of electric ranges,
wall-mounted ovens, counter-mounted cooking units,
clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be
connected ta the grounded circuit conductor if all the
following conditions are met.

(1) The supply circuit is 120/240-volt, single-phase, 3-
wire; or 208Y/120-volt derived from a 3-phase, 4-wire, wye-
connected system.

(2) The grounded conductor is not smaller than 10 A WG
copper or 8 A WG aluminum.

(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE service-entrance
cable and the branch circuit originates at the service equipment.

(4) Grounding contacts of receptacles fiAmished as part of
the equipment are bonded to the equipment.

250.142 Use of Grounded Circuit Conductor for
Grounding Equipment.

(A) Supply-Side Equipment. A grounded circuit
conductor shall be permitted to ground non-current-
carrying metal parts of equipment, raceways, and other
enclosures at any of the following locations:

(1) On the supply side or within the enclosure of the ac
service -disconnecting means

(2) On the supply side or within the enclosure of the main
disconnecting means for separate buildings as
provided in 250.32(B)

(3) On the supply side or within the enclosure of the main
disconnecting means or overcurrent devices of a
separately derived system where permitted by
250.30(A)(1)

(B) Load-Side Equipment. Except as permitted in
250.30(A)(1) and 250.32(B), a grounded circuit conductor
shall not be used for grounding non-current-carrying metal
parts of equipment on the load side of the service
disconnecting means or on the load side of a separately
derived system disconnecting means or the overcurrent
devices for a separately derived system not having a main
disconnecting means.

Exception No. 1: The frames of ranges, wall-mounted
ovens, counter-mounted cooking units, and clothes dryers
under the conditions permitted for existing installations by

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ARTICLE 250 - GROUNDING AND BONDING

250.148

250. 140 shall be permitted to be fonnected to the grounded
circuit conductor.

Exception No. 2: It shall be permissible to ground meter
enclosures by connection to the grounded circuit conductor
on the load side of the service disconnect where all of the
following conditions apply:

(1) No service ground-fault protection is installed.

(2) All meter enclosures are located immediately
adjacent to the service disconnecting means.

(3) The size of the grounded circuit conductor is not
smaller than the size specified in Table 250.122 for
equipment grounding conductors.

Exception No. 3: Direct-current systems shall be permitted
to be grounded on the load side of the disconnecting means
or overcurrent device in accordance with 250.164.

Exception No. 4: Electrode-type boilers operating at over
600 volts shall be grounded as required in 490.72(E)(1)
and 490.74.

250.144 Multiple Circuit Connections. Where equipment
is grounded and is supplied by separate connection to more
than one circuit or grounded premises wiring system, ail
equipment LS?^M4*TO: conductor , termination shall be
provided for each such connection as specified in 250.134
and 250.138.

250.146 Connecting Receptacle Grounding Terminal to

Box. An equipment bonding jumper shall be used to
connect the grounding terminal of a grounding-type
receptacle to a grounded box unless grounded as in
250.146(A) through (D). The equipment bonding jumpet]
shall be sized, in acdordance witli Table 250, 122 based on
tiie rating of the overcurrent device protecting the circuri
ponductoifs.

(A) Surface-Mounted Box. Where the box is mounted on
the surface, direct metal-to-metal contact between the
device yoke and the box or a contact yoke or device that
complies with 250.146(B) shall be permitted to ground the
receptacle to the box. At least one of the insulating washers
shall be removed from receptacles that do not have a
contact yoke or device that complies with 250, 146(B) to
ensure direct metal-to-metal contact. This provision shall
not apply to cover-mounted receptacles unless the box and
cover combination are listed as providing satisfactory
ground continuity between the box and the receptacle, i^
listed: exposed ^ork cover shall be' peim the'
grounding and bonding m^ (1) the device „i$
attached to the ; coyer with at least two fasteiibrs that ar^^
jperm^netit ; (stxch ^s ; a rivet): or have :a thread Jockmg ot;
sctew lodkittg ; meaES and (2) when the coyer: tndunting
ibpi^s are located pri a flat toa-tms^^

(B) Contact Devices or Yokes. Contact devices or yokes
designed and listed as self-grounding shall be permitted in
conjunction with the supporting screws to establish the

grounding circuit between the device yoke and flush-type

boxes.

(C) Floor Boxes. Floor boxes designed for and listed as
providing satisfactory ground continuity between the box
and the device shall be permitted.

(D) Isolated Receptacles. Where instaiied for the

reduction of electrical noise (electromagnetic interference)
on the grounding circuit, a receptacle in which the
grounding terminal is purposely insulated from the
receptacle mounting means shall be permitted. The
receptacle grounding terminal shall be [connected to an
insulated equipment grounding conductor run with the
circuit conductors. This l^mpinent grounding conductor
shall be permitted to pass through one or more panelboards
without I connection to the panelboard grounding terminal
|)a| as permitted in 408.40, Exception, so as to terminate
within the same building or structure directly at an
equipment grounding conductor terminal of the applicable
derived system or service. [Where installed in accordance
with t% provisions Qf this, section, this equipment
grounding „ c^onducto^^ to pass

teou^bpxeA 3Yit?^^y^/Ar„<>^^h^t^ishclosur^^ without being
connecied to such enclosures.

FPN: Use of an isolated equipment grounding conductor
does not relieve the requirement for grounding the raceway
system and outlet box.

250.148 Continuity and Attachment of Equipment
Grounding Conductors to Boxes. Where circuit
conductors are spliced within a box, or terminated on
equipment within or supported by a box, any equipment
grounding conductor(s) associated with those circuit
conductors shall be connected within the box or to the box
with devices suitable for the use in accordance with
250. 148(A) through (E).

Exception: The equipment grounding conductor permitted
in 250.146(D) shall not be required to be eomected to the
other equipment grounding conductors or to the box.

(A) Connections. Connections and spHces shall be made in
accordance with 1 10.14(B) except that insulation shall not
be required.

(B) Grounding Continuity. The arrangement of grounding
connections shall be such that the disconnection or the
removal of a receptacle, luminaire, or other device fed from
the box does not interfere with or interrupt the grounding
continuity.

(C) Metal Boxes. A connection shall be made between the
one or more equipment grounding conductors and a metal
box by means of a grounding screw that shall be used for
no other purpose, equipment listed for grpu^ or a
listed grounding device.

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250.160

ARTICLE 250 - GROUNDING AND BONDING

(D) Non metallic Boxes. One or more equipment grounding
conductors brought into a nonmetallic outlet box shall be
arranged such that a connection can be made to any fitting
or device in that box requiring grounding.

(E) Solder. Connections depending solely on solder shall
not be used.

VIII. Direct-Current Systems

250.160 General. Direct-current systems shall comply
with Part VIII and other sections of Article 250 not
specifically intended for ac systems.

250.162 Direct-Current Circuits and Systems to Be
Grounded.. Direct-current circuits and systems shall be
grounded as provided for in 250.162(A) and (B).

(A) Two-Wire, Direct-Current Systems. A 2-wire, dc
system supplying premises wiring and operating at greater
than 50 volts but not greater than 300 volts shall be grounded.

Exception No. 1: A system equipped with a ground
detector and supplying only industrial equipment in limited
areas shall not be required to be grounded.

Exception No. 2: A rectifier-derived dc system supplied
from an ac system complying with 250.20 shall not be
required to be grounded.

Exception No. 3: Direct-current fire alarm circuits having
a maximum current of 0.030 ampere as specified in Article
760, Part III, shall not be required to be grounded.

(B) Three-Wire, Direct-Current Systems. The neutral
conductor of all 3-wire, dc systems supplying premises
wiring shall be grounded.

250.164 Point of Connection for Direct-Current
Systems.

(A) Off-Premises Source. Direct-current systems to be
grounded and supplied from an off-premises source shall
have the grounding connection made at one or more supply
stations. A grounding connection shall not be made at
individual services or at any point on the premises wiring.

(B) On-Premises Source. Where the dc system source is
located on the premises, a grounding connection shall be
made at one of the following:

(1) The source

(2) The first system disconnection means or overcurrent device

(3) By other means that accomplish equivalent systern
protection and that utilize equipment listed and
identified for the use

250.166 Size of the Direct-Current Grounding Electrode
Conductor. The size of the grounding electrode conductor
for a dc system shall be as specified in 250.166(A) and;(iB),'

bxcept a^^'getmi^^ through (E).

(A) Not Smaller Than the Neutral Conductor. Where the
dc system consists of a 3 -wire balancer set or a balancer
winding with overcurrent protection as provided in
445.12(D), the grounding electrode conductor shall not be
smaller than the neutral conductor and not smaller than 8
AWG copper or 6 AWG aluminum.

(B) Not Smaller Than the Largest Conductor. Where the
dc system is other than as in 250.166(A), the grounding
electrode conductor shall not be smaller than the largest
conductor suppHed by the system, and not smaller than 8
AWG copper or 6 AWG aluminum.

(C) Connected to Rod, Pipe, or Plate Electrodes. Where
cormected to rod, pipe, or plate electrodes as in
250.52(A)(5) or (A)(7), that porfion of the grounding
electrode conductor that is the sole connection to the
grounding electrode shall not be required to be larger than
6 AWG copper wire or 4 AWG aluminum wire.

(D) Connected to a Concrete-Encased Electrode. Where
connected to a concrete-encased electrode as in
250.52(A)(3), that portion of the grounding electrode
conductor that is the sole connection to the grounding
electrode shall not be required to be larger than 4 AWG
copper wire.

(E) Connected to a Ground Ring. Where connected to a
ground ring as in 250.52(A)(4), that portion of the
grounding electrode conductor that is the sole connecfion to
the grounding electrode shall not be required to be larger
than the conductor used for the ground ring.

250.168 Direct-Current ^ystey Bonding Jumper. For
idirect*-cuitent systems that are to be grounded, anunspliced,
|»ondingjmpper_sh^^^

boutce 'Of ;ttie3t?L?X?tg!7^/,di^M9^^ ^^.

jsysterri; is grounded.; The size of the bonding jumper shall
not be smaller than the system grounding electrode
conductor specified in 250.166 and slmil com^^ thd

p^pvi^ion^ of 250.28{A^^ {G)\

250.169 Ungrounded Direct-Current Separately
Derived Systems. Except as otherwise permitted in 250.34
for portable and vehicle-mounted generators, an
ungrounded dc separately derived system supplied from a
stand-alone power source (such as an engine-generator set)
shall have a grounding electrode conductor connected to an
electrode that complies with Part III of this article to
provide for grounding of metal enclosures, raceways,
cables, and exposed non-current-carrying metal parts of

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2010 California Electrical Code

ARTICLE 250 - GROUNDING AND BONDING

250.184

equipment. The grounding electrode conductor connection
shall be to the metal enclosure at any point on the
separately derived system from the source to the first
system disconnecting means or overcurrent device, or it
shall be made at the source of a separately derived system
that has no disconnecting means or overcurrent devices.

The size of the grounding electrode conductor shall be
in accordance with 250.166.

IX. Instruments, Meters, and Relays

250.170 Instrument Transformer Circuits. Secondary
circuits of current and potential instrument transformers shall
be grounded where the primary windings are connected to
circuits of 300 vohs or more to ground and, where on
switchboards, shall be grounded irrespective of voltage.

Exception No. 1: Circuits where the primary windings are
connected to circuits of less than 1000 volts with no live
parts or wiring exposed or accessible to other than
qualified persons.

Exception No. 2: Cuwent transformer secondaries

fe(ftdrtd ib' begrounded:

250.172 Instrument Transformer Cases. Cases or

frames of instrument transformers shall be Connected to the
equipmeBt gr^^ conductor where accessible to other

than qualified persons.

Exception: Cases or frames of current transformers, the
primaries of which are not over 150 volts to ground and
that are used exclusively to supply current to meters.

250.174 Cases of Instruments, Meters, and Relays
Operating at Less Than 1000 Volts. Instruments, meters,
and relays operating with windings or working parts at less
than 1000 volts shall be lqonnec|e§;^^^
§§5]^Sg[S)n4ucto as specified in 250.174(A), (B), or (C).

(A) Not on Switchboards. Instruments, meters, and relays
not located on switchboards, operating with windings or
working parts at 300 volts or more to ground, and
accessible to other than qualified persons, shall have the
cases and other exposed metal parts connected to the
equipment grounding conductor.

(B) On Dead-Front Switchboards. Instruments, meters,
and relays (whether operated from current and potential
transformers or connected directly in the circuit) on
switchboards having no live parts on the front of the panels
shall have the cases coBnected tO:iiejequi£mett^^
Iponductoi

(C) On Live-Front Switchboards. Instruments, meters,
and relays (whether operated from current and potential
transformers or connected directly in the circuit) on
switchboards having exposed live parts on the front of
panels shall not have their cases connected to thq
equipmeaf grounding cpjaduc^^ Mats of insulating rubber
or other suitable floor insulation shall be provided for the
operator where the voltage to ground exceeds 150.

250.176 Cases of Instruments, Meters, and Relays —
Operating Voltage 1 kV and Over. Where instruments,
meters, and relays have current-carrying parts of 1 kV and
over to ground, they shall be isolated by elevation or
protected by suitable barriers, grounded metal, or insulating
covers or guards. Their cases shall not be connected to thd
bquipment grounding conductor.

Exception: Cases of electrostatic ground detectors where
the internal ground segments of the instrument are
connected to the instrument case and grounded and the
ground detector is isolated by elevation.

250.178 Instrument Grounding Conductor. The

bqtiipment grounding conductor for secondary circuits of
instrument transformers and for instrument cases shall not
be smaller than 12 AWG copper or 10 AWG aluminum.
Cases of instrument transformers, instruments, meters, and
relays that are mounted directly on grounded metal surfaces
of enclosures or grounded metal switchboard panels shall
be considered to be grounded, and no additional jequipinent
grounding conductor shall be required.

X. Grounding of Systems and Circuits of 1 kV and
Over (High Voltage)

250.180 General. Where high-voltage systems are
grounded, they shall comply with all applicable provisions
of the preceding sections of this article and with 250.182
through 250.190, which supplement and modify the
preceding sections.

250.182 Derived Neutral Systems. A system neutral
^1^1 derived from a grounding transfr)rmer shall be
permitted to be used for grounding high- voltage systems.

250.184 Solidly Grounded Neutral Systems. Solidly
grounded neutral systems shall be permitted to be either
single point grounded or multigrounded neutral.

(A) Neutral Conductor.

(1) Insulation Level. The minimum insulation level for neutral
conductors of soUdly grounded systems shall be 600 volts.

Exception No. 1: Bare copper conductors shall be permitted
to be used for the neutral conductor of the following:

(1) 'Spyice-mtrance conductors

(2) 'Sejyicejgterals^

(3) Direct-buried pon^^^ offeeders\

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250.186

ARTICLE 250 - GROUNDING AND BONDING

Exception No. 2: Bare conductors shall be permitted for the
neutral conductor of overhead portions installed outdoors.
Exception No. 3: The grounded neutral conductor' shall be
permitted to be a bare conductor if isolated from phase
conductors and protected from physical damage.

FPN: See 225.4 for conductor covering where within 3.0 m
(10 ft) of any building or other structure.

(2) Ampacity. The neutral conductor shall be of sufficient
ampacity for the load imposed on the conductor but not less
than 33 V3 percent of the ampacity of the phase conductors.
Exception: In industrial and commercial premises under
engineering supervision, it shall be permissible to size the
ampacity of the neutral conductor to not less than 20
percent of the ampacity of the phase conductor.

(B) Single-Point Grounded Neutral System. Where a
single-point grounded neutral system is used, the following
shall apply:

(1) A single-point grounded neutral system shall be
permitted to be supplied from (a) or (b):

a. A separately derived system

b. A multigrounded neutral system with an equipment
grounding conductor cormected to the
multigrounded neutral ;cohductor at the source of
the single-point grounded heutxal system

(2) A grounding electrode shall be provided for the
system.

(3) A grounding electrode conductor shall connect the
grounding electrode to the system neutral jconductor,

(4) A bonding jumper shall connect the equipment
grounding conductor to the grounding electrode
conductor.

(5) An equipment grounding conductor shall be provided
to each building, structure, and equipment enclosure.

(6) A neutral conductor shall only be required where
phase-to-neutral loads are supplied.

(7) The neutral conductor,; where provided, shall be
insulated and isolated from earth except at one
location.

(8) An equipment grounding conductor shall be run
with the phase conductors and shall comply with
(a), (b), and (c):

a. Shall not carry continuous load

b. May be bare or insulated

c. Shall have sufficient ampacity for fault current duty

(1) The neutral conductor of a sohdly grounded neutral
system shall be permitted to be grounded at more than
one point. Grounding shall be permitted at one or more
of the following locations:

a. Transformers supplying conductors to a building or
other structure

b. Underground circuits where the neutral gondUcte^ is
exposed

c. Overhead circuits installed outdoors

(2) The multigrounded neutral conductor shall be grounded

at each transformer and at other additional locations by
connection to a grounding electrode.

(3) At least one grounding electrode shall be installed and
connected to the multigrounded neutral conductor
every 400 m (1300 ft).

(4) The maximum distance between any two adjacent
electrodes shall not be more than 400 m (1300 ft).

(5) In a multigrounded shielded cable system, the shielding
shall be grounded at each cable joint that is exposed to
personnel contact.

250*186 Impedance Grounded Neutral Systems.

Impedance grounded neutral systems in which a grounding
impedance, usually a resistor, Hmits the ground- fault
current shall be permitted where all of the following
conditions are met:

(1) The conditions of maintenance and supervision ensure
that only qualified persons service the installation.

(2) Ground detectors are installed on the system.

(3) Line-to -neutral loads are not served.

Impedance grounded neutral systems shall comply
with the provisions of 250.186(A) through (D).

(A) Location. The grounding impedance shall be inserted
in the grounding conductor between the grounding
electrode of the supply system and the neutral point of the
supply transformer or generator.

(B) Identified and Insulated. The neutral conductor of an
impedance grounded neutral system shall be identified, as
well as fully insulated with the same insulation as the phase
conductors.

(C) System Neutral jConductorl Connection. The system
neutral conductor shall not be connected to ground, except
through the neutral grounding impedance.

(D) Equipment Grounding Conductors. Equipment
grounding conductors shall be permitted to be bare and
shall be electrically connected to the ground bus and
grounding electrode conductor.

250.188 Grounding of Systems Supplying Portable or
Mobile Equipment. Systems supplying portable or
mobile high-voltage equipment, other than substations
installed on a temporary basis, shall comply with
250.188(A) through (F).

(A) Portable or Mobile Equipment. Portable or mobile
high- voltage equipment shall be supplied from a system
having its neutral Jc6ridp.Qtor; grounded through an
impedance. Where a delta-connected high-voltage system

70-122

2010 California Electrical Code

ARTICLE 280 - SURGE ARRESTERS, OVER 1 kV

280.5

is used to supply portable or mobile equipment, a system
neutral jjoSOffld; associated neutral cS^Ectpi^ shall be
derived.

(B) Exposed Non-Current-Carrying Metal Parts.

Exposed non-current-carrying metal parts of portable or
mobile equipment shall be connected by an equipment
grounding conductor to the point at which the system
neutral impedance is grounded.

(C) Ground-Fault Current. The voltage developed
between the portable or mobile equipment frame and
ground by the flow of maximum ground- fault current shall
not exceed 100 volts.

(D) Ground-Fault Detection and Relaying. Ground-fault
detection and relaying shall be provided to automatically
de-energize any high-voltage system component that has
developed a ground fault. The continuity of the equipment
grounding conductor shall be continuously monitored so as
to de-energize automatically the high-voltage circuit to the
portable or mobile equipment upon loss of continuity of the
equipment grounding conductor.

(E) Isolation. The grounding electrode to which the
portable or mobile equipment system neutral impedance is
connected shall be isolated from and separated in the
ground by at least 6.0 m (20 ft) fi-om any other system or
equipment grounding electrode, and there shall be no direct
connection between the grounding electrodes, such as
buried pipe and fence, and so forth.

(F) Trailing Cable and Couplers. High-voltage trailing
cable and couplers for interconnection of portable or
mobile equipment shall meet the requirements of Part III of
Article 400 for cables and 490.55 for couplers.

250.190 Grounding of Equipment. All non-current-
carrying metal parts of fixed, portable, and mobile
equipment and associated fences, housings, enclosures, and
supporting structures shall be grounded.

Exception: Where isolated from ground and located so as
to prevent any person who can make contact with ground
from contacting such metal parts when the equipment is
energized.

Equ?j:>menl grounding conductors not an integral part
of a cable assembly shall not be smaller than 6 AWG
copper or 4 AWG aluminum.

FPN: See 250.110, Exception No. 2, for pole-mounted
distribution apparatus.

I. General

280.1 Scope. This article covers general requirements,
installation requirements, and connection requirements for surge
arresters installed on premises wiring systems over 1 kV.

psMlftii:!Fhere:^

280.3 Number Required. Where used at a point on a
circuit, a surge arrester shall be connected to each
ungrounded conductor. A single installation of such surge
arresters shall be permitted to protect a number of
interconnected circuits, provided that no circuit is exposed
to surges while disconnected from the surge arresters.

280.4 Surge Arrester Selection. ^\ip ^w%^ w^BpiB ^^

gompiy^wthjm and (B).

j[A) Ratog* Th^^ rato be eqiial to

^r greater tliati the maxkmm oggmto^ votoge

Available at the point of appUoaijQn]

^Mi&jCm^^^ 0|)etatitig voltage shaflbe the phase^o^gtoiaiid

j^J^ ;^Imp€dan^^PX ;Uii'grduaded ;''|ystei5- ;Thejoaa|pmuiiT(
pptttinu^p^s operating voltage shall; be Jie |jfliase*t<>"phase

vqikge;oftlie^systejS

(B) Silicon Carbide Types. The rating of a silicon carbide-
type surge arrester shall be not less than 125 percent of the
taiag specified iti 286.4(A).!

FPN No. 1 : For further information on surge arresters, see
ANSI/IEEE C62. 11-2005, Standard for Metal-Oxide Surge
Arresters for Alternating-Current Power Circuits ^I--fcVJ^_
and ANSI/IEEE C62.22-1997, Guide for the Application of
Metal-Oxide Surge Arresters for Alternating-Current
Systems.

FPN No. 2: The selection of a properly rated metal oxide
arrester is based on considerations of maximum continuous
operating voltage and the magnitude and duration of
overvoltages at the arrester location as affected by phase-to-
ground faults, system grounding techniques, switchin
surges, and other causes. See the manufacturer's appHcation
rules for selection of the specific arrester to be used at a
particular location.

2010 California Electrical Code

70-123

280.11

ARTICLE 285 - SURGE-PROTECTIVE DEVICES (SPDs), 1 kV OR LESS

280.5 jUbstiiig^^A^ ^ncstm shall be a listed device^
II. Installation

280.11 Location. Surge arresters shall be permitted to be
located indoors or outdoors. Surge arresters shall be made
inaccessible to unqualified persons, unless listed for
installation in accessible locations.

280.12 Routing of Surge Arrester (Sroiiiiidiiig
Conductors.; The conductor used to connect the surge
arrester to line, bus, or equipment and to a gr6Mdiilg
conductor cqnipteption point as provided in 280,21: shall not
be any longer than necessary and shall avoid unnecessary
bends.

III. Connecting Surge Arresters

280.21 'Qonmctipni The arrester grounding conductor
shall be connected to one of the following:

(1) Grounded service conductor

(2) Grounding electrode conductor

(3) Grounding electrode for the service

(4) Equipment grounding terminal in the service equipment

280.23 Siirge-Arrester Conductors. The conductor
between the surge arrester and the line and the surge
arrester and the grounding connection shall not be smaller
than 6 AWG copper or aluminum.

280.24 Intercoiiiiectipiis. The grounding conductor of a
surge arrester protecting a transformer that supplies a
secondary distribution system shall be interconnected as
specified in 280.24(A), (B), or (C).

(A) Metallic Interconnections. A metallic interconnection
shall be made to the secondary grounded circuit conductor
or the secondary circuit grounding conductor provided that,
in addition to the direct grounding connection at the surge
arrester, the following occurs:

(1) Additional Gronndlng Connectioii. The grounded
conductor of the secondary has elsewhere a grounding
connection to a continuous metal underground water piping
system. In urban water-pipe areas where there are at least
four water-pipe connections on the neutral conductor; and
not fewer jthan four such connections in each mile of
neutral ^cohductor^ the metallic interconnection shall be
permitted to be made to the secondary neutral conductor
with omission of the direct grounding connection at the
surge arrester.

(2) MnltigrpuMe^^^^ The

grounded conductor of the secondary system is a part of a
multigrouiided neutral system or static wire of which the
primary neutral conductor or static wire has at least four
grounding connections in each mile of line in addition to a
grounding connection at each service.

(B) Through Spark Gap or Device. Where the surge
arrester grounding conductor is not connected as in
280.24(A) or where the secondary is not grounded as in
280.24(A) but is otherwise grounded as in 250.52, an
interconnection shall be made through a spark gap or listed
device as required by (B)(1) or (B)(2):

(1) jUnground^d orlDnigrpuiided JPr^^^ System. For

ungrounded or unigrounded primary systems, the spark gap
or listed device shall have a 60-Hz breakdown voltage of at
least twice the primary circuit voltage but not necessarily
more than 10 kV, and there shall be at least one other
ground on the grounded conductor of the secondary that is
not less than 6.0 m (20 ft) distant from the surge-arrester
grounding electrode.

(2) Miultigrounded l Neutral Mmar^ System. For

multigrounded neutral primary systems, the spark gap or
listed device shall have a 60-Hz breakdown of not more than
3 kV, and there shall be at least one other ground on the
grounded conductor of the secondary that is not less than 6.0
m (20 ft) distant from the surge-arrester grounding electrode.

(C) By Special Permission. An interconnection of the
surge-arrester ground and the secondary neutral Conductor,
other than as provided in 280.24(A) or (B), shall be
permitted to be made only by special permission.

280.25 Grounding Conductor Connections
'Enclosures. Except as indicated in this article, surge-arrester
grounding conductor connections shall be made as specified in
Article 250, Parts HI and X. Grounding conductors installed in
metal enclosures shall corriply with 250.64(E).:

ARtlCLE285

^urge-Protective Devices (SPPs)^ 1 kV or Less

I. General

285.1 Scope. This article covers general requirements,
installation requirements, and connection requirements for
SFDs [surge arresters and transient voltage surge
suppressors (TTVSSs)] permanently installed on premises
wiring systems 1 kV or less.

fGPNlSlp, 1: Surge arresters less ihani_^k\^re also koo as
type 1 SFBs:

JFPN No* 2: Transient yoltage ; surge suppressors (TVSSs)

ate also known as Type 2 and TypeXSPDs;.;

285.3 Uses Not Permitted. |An Sffi^j^urg^
pPVSS); device shall not be installed in the following:

70-124

2010 California Electrical Code

ARTICLE 285 - SURGE-PROTECTIVE DEVICES (SPDs), 1 kV OR LESS

285.2a

( 1 ) Circuits exceeding [l kV

(2) On ungrounded systems, impedance grounded systems,
or comer grounded delta systems unless listed
specifically for use on these systems.

(3) Where the rating of the SFD (surge an-ester or l^SSJ is less

than the maximum continuous phase-to-ground power
frequency voltage available at the point of application

FPN: For further information on S?M (SEISSIS see NEMA
LS 1-1992, Standard for Low Voltage Surge Suppression
Devices. The selection of a properly rated SFl!)'(TySS) is
based on criteria such as maximum continuous operating
voltage, the magnitude and duration of overvoltages at the
suppressor location as affected by phase-to-ground faults,
system grounding techniques, and switching surges.

285.4 Number Required. Where used at a point on a
circuit, the SroP;:|sUfgb^;Ja&es^ shall be
connected to each ungrounded conductor.

285.5 Listing. An SPD (surg^ OT^ester or tySS)' shall be a
listed device.

285.6 Sliort-Circuit Current Rating. The SPD (surge

lirester 6f TySSJ shall be marked with a short-circuit
current rating and shall not be installed at a point on the
system where the available fault current is in excess of that
rating. This marking requirement shall not apply to
receptacles,

II. Installation

285.11 Location. jsro§j|$jy;g4'.w^s1^^: o?:!^^ shall
be permitted to be located indoors or outdoors and shall be
made inaccessible to unqualified persons, unless listed for
installation in accessible locations.

285.12 Routing of Connections. The conductors used to

connect the MD| (surge anrestet or T^^ to the line or bus
and to ground shall not be any longer than necessary and
shall avoid unnecessary bends.

IIL Connecting SPDs.

285.21 Connection. Where an iSPEi (smge ;atteste?^ ot
ifySS) device is installed, it shall comply with 285.23,
through 285,28.

285 J3 Type 1 SPDs (Surge Arresters)*

Type 1 SPDs shall be installed in accordance witH

a85:23(A)W®

(A) Jiistallatiott*_; T^e J 1: ^SpDs (sui'ge arresters)' | shajT be'

In^fedias follows^

(1) jType 1 SPi>s (surge an^esters) shall be perniitted to bq
connected to the supply side of the service disconnept
^s perrnittad in 230.82(4) pi;

(2) Type ,1 SPDs (^ge arresters) shall be perniitted to be
botoec^ in 285;24;

(B) At vthe; Service, When irist^lWd : at : seraces^ tlie
grpuhding pohductor x)f a Type 1: S]pi)i$&ll:be connected: ^to
oneof;fcjK|lqy^

(1) Giw£dfedser^

(2) Orduniiing electrode condwtdr

(3) Grounding electrode for the service

(4) Equipment grounding terminal in the service equipment

285^4:T^g;2:SI^^:C^

fType 2! SPD^ (TV SSs) skail :l^e installed in. accordance Wiffi

i(A)| Service-Supplied Building or Structure. pType i

;SPD$ (TVSSs) shall be connected anywhere on the load
side of a service disconnect overcurrent device required in
230.91, unless installed in accordance with 230.82(8).

(B) Feeder-Supplied Building or Structure.^!rype 2 SPD^

(TVSSs)! shall be connected s^l :0i^;;bmi4^ sfructui^
anywhere] on the load side of the first overcurrent device at
the building or structure.

(C) Separately Derived System. The SPD (TVSS) shall
be connected on the load side of the first overcurrent device
in a separately derived system.

285.25 Type 3 SPDs. Type 3 SPDs (TVSSs) shall be
permitted to be installed anywhe^re on the load side of
branch^circuit dvetcuirent protection up to the equipment
served,^ provided the connection is a minimum 10 m (30 ftj
bf conductor : distance firqm the sei^^^ sepfarately

idetiy ed system disconnect;

285.2<^ Conductor Size. Line and grounding conductors shall
not be smaller than 14 AWG copper or 12 AWG aluminum.

285.27^ Connection Between Conductors. An SPD (surge;
aTOSter or TVSS) shall be permitted to be connected
between any two conductors — ungrounded conductor(s),
grounded conductor, grounding conductor. The grounded
conductor and the grounding conductor shall be
interconnected only by the normal operation of the SPD
(surge arrester or TVSS) during a surge.

285.28 Grounding Conductor ConnectiQiis and
Enclosures* Except as indicated in this article, SPD
grounding cotitiections shall be made as specified in Axticle
250, Part ni Grounding conductors imstalled in metal
ienclosures shall comply with 250,64(E)-

2010 California Electrical Code

70-125

CHAPTER 3 CALIFORNIA MATRIX ADOPTION TABLE

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2.
70-125.1 2010 California Electrical Code

CHAPTER 3 CALIFORNIA MATRIX ADOPTION TABLE

CHAPTER 3 -WIRING METHODS AND MATERIALS

Adopting Agency

BSC

SFM

HOD

DSA

OSHPD

DPH

ss/cc

Adopt Entire Chapter

Adopt Entire Chapter as amended
(amended sections listed below)

Adopt only those articles / sections that
are listed below

Article / Section

334/334.10

334.12

394/394.12

The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is appHcable to structures subject to HOD 1 and/or HOD 2.
2010 Cahfomia Electrical Code 70-125.2

CHAPTER 3

ARTICLE 300 - WIRING METHODS

Chapter 3 Wiring Methods and Materials

ARTICLE 300

Wiring Methods

I. General Requirements
300.1 Scope.

(A) All Wiring Installations. This article covers wiring
methods for all wiring installations unless modified by
other articles.

(B) Integral Parts of Equipment. The provisions of this
article are not intended to apply to the conductors that form
an integral part of equipment, such as motors, controllers,
motor control centers, or factory assembled control
equipment or listed utilization equipment.

designators and trade sizes for conduit, tubing, and
associated fittings and accessories shall be as designated in
Table 300.1(C).

I Table 300.1(C) Metric Designators and Trade Sizes

Metric
Designator

Trade
Size

12
16
21
27
35
41
53
63
78
91
103
129
155

V/2

2^2

3/2

4
5
6

Note: The metric designators and trade sizes are for identification
purposes only and are not actual dimensions.

300.2 Limitations.

(A) Voltage. Wiring methods specified in Chapter 3 shall
be used for 600 volts, nominal, or less where not
specifically limited in some section of Chapter 3. They
shall be permitted for over 600 volts, nominal, where
specifically permitted elsewhere in this Code.

(B) Temperature. Temperature hmitation of conductors
shall be in accordance with 310.10.

300.3 Conductors.

(A) Single Conductors, Single conductors specified in
Table 310.13(A) shall only be installed where part of a
recognized wiring method of Chapter 3.

Exception: Individual conductors shall be permitted where
installed as separate overhead conductors in accordance
with 225. 6.

(B) Conductors of the Same Circuit. All conductors of
the same circuit and, where used, the grounded conductor
and all equipment grounding conductors and bonding
conductors shall be contained within the same raceway,
auxiliary gutter, cable tray, cablebus assembly, trench,
cable, or cord, unless otherwise permitted in accordance
with 300.3(B)(1) through (B)(4).

(1) Paralleled Installations. Conductors shall be permitted to
be run in parallel in accordance with the provisions of 310.4.
The requirement to run all circuit conductors within the same
raceway, auxiliary gutter, cable tray, trench, cable, or cord shall
apply separately to each portion of the paralleled installation,
and the equipment grounding conductors shall comply with the
provisions of 250.122. Parallel runs in cable tray shall comply
with the provisions of 392.8(D).

Exception: Conductors installed in nonmetallic raceways
run underground shall be permitted to be arranged as
isolated phase installations. The raceways shall be
installed in close proximity, and the conductors shall
comply with the provisions of 300.20(B).

(2) Grounding and Bonding Conductors. Equipment
grounding conductors shall be permitted to be installed
outside a raceway or cable assembly where in accordance
with the provisions of 250.130(C) for certain existing
installations or in accordance with 250.134(B), Exception
No. 2, for dc circuits. Equipment bonding conductors shall
be permitted to be installed on the outside of raceways in
accordance with 250.102(E).

(3) Nonferrous Wiring Methods. Conductors in wiring
methods with a nonmetallic or other nonmagnetic sheath,
where run in different raceways, auxihary gutters, cable
trays, trenches, cables, or cords, shall comply with the
provisions of 300.20(B). Conductors in single-conductor
Type MI cable with a nonmagnetic sheath shall comply
with the provisions of 332.31. Conductors of single-
conductor Type MC cable with a nonmagnetic sheath shall
comply with the provisions of 330.31, 330,116, and
300.20(B).

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2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.4

(4) Enclosures. Where an auxiliary gutter runs between a
column-width panelboard and a pull box, and the pull box
includes neutral terminations, the neutral conductors of
circuits suppHed from the panelboard shall be permitted to
originate in the pull box.
(C) Conductors of Different Systems.

(1) 600 Volts, Nominal, or Less. Conductors of kc^andjdg
circuits, rated 600 volts, nominal, or less, shall be permitted
to occupy the same equipment wiring enclosure, cable, or
raceway. All conductors shall have an insulation rating
equal to at least the maximum circuit voltage applied to any
conductor within the enclosure, cable, or raceway.
Exception: For solar photovoltaic systems in accordance
with 690,4 (B).

FPN: See 725.|36iA) for Class 2 and Class 3 circuit
conductors.

(2) Over 600 Volts, Nominal. Conductors of circuits rated
over 600 volts, nominal, shall not occupy the same
equipment wiring enclosure, cable, or raceway with
conductors of circuits rated 600 volts, nominal, or less
unless otherwise permitted in (C)(2)(a) through (C)(2)(e).

(a) Secondary wiring to electric-discharge lamps of
1000 volts or less, if insulated for the secondary voltage
involved, shall be permitted to occupy the same luminaire,
sign, or outline lighting enclosure as the branch-circuit
conductors.

(b) Primary leads of electric-discharge lamp ballasts
insulated for the primary voltage of the ballast, where
contained within the individual wiring enclosure, shall be
permitted to occupy the same luminaire, sign, or outhne
lighting enclosure as the branch-circuit conductors.

(c) Excitation, control, relay, and ammeter conductors
used in connection with any individual motor or starter
shall be permitted to occupy the same enclosure as the
motor-circuit conductors.

(d) In motors, switchgear and control assemblies, and
similar equipment, conductors of different voltage ratings
shall be permitted.

(e) In manholes, if the conductors of each system are
permanently and effectively separated from the conductors
of the other systems and securely fastened to racks,
insulators, or other approved supports, conductors of
different voltage ratings shall be permitted.

Conductors having nonshielded insulation and
operating at different voltage levels shall not occupy the
same enclosure, cable, or raceway.

300.4 Protection Against Physical Damage. Where
subject to physical damage, conductors shall be protected.
(A) Cables and Raceways Through Wood Members.
(1) Bored Holes. In both exposed and concealed locations,
where a cable- or raceway-type wiring method is installed
through bored holes in joists, rafters, or wood ^members,
holes shall be bored so that the edge of the hole is not less
than 32 mm (VA in.) from the nearest edge of the wood

member. Where this distance cannot be maintained, the
cable or raceway shall be protected from penetration by
screws or nails by a steel plate(si) or bushing(s)|, at least 1.6
mm (1/16 in.) thick, and of appropriate length and width
installed to cover the area of the wiring.
Exception No. 1: Steel plates shall not be required to
protect rigid metal conduit, intermediate metal conduit,
rigid nonmetaUic conduit, or electrical metallic tubing.
Exception No. 2: A listed and marked steel plate less than
1.6 mm (1/16 in.) thick that provides equal or better
protection against nail or screw penetration shall be
permitted.

(2) Notches in Wood. Where there is no objection because
of weakening the building structure, in both exposed and
concealed locations, cables or raceways shall be permitted
to be laid in notches in wood studs, joists, rafters, or other
wood members where the cable or raceway at those points
is protected against nails or screws by a steel plate at least
1.6 mm (1/16 in.) thick, and of appropriate length and
width, installed to cover the area of the wiring. The steel
plate shall be installed before the building finish is apphed.
Exception No. 1: Steel plates shall not be required to
protect rigid metal conduit, intermediate metal conduit,
rigid nonmetaUic conduit, or electrical metallic tubing.
Exception No. 2: A listed and marked steel plate less than
1.6 mm (1/16 in.) thick that provides equal or better
protection against nail or screw penetration shall be
permitted.

(B) Nonmetallic-Sheathed Cables and Electrical
NonmetaUic Tubing Through Metal Framing Members.

(1) Nonmetallic-Sheathed Cable. In both exposed and
concealed locations where nonmetaUic- sheathed cables
pass through either factory- or field-punched, cut, or drilled
slots or holes in metal members, the cable shall be
protected by listed bushings or listed grommets covering all
metal edges that are securely fastened in the opening prior
to installation of the cable.

(2) Nonmetallic-Sheathed Cable and Electrical
NonmetaUic Tubing. Where nails or screws are likely to
penetrate nonmetallic-sheathed cable or electrical
nonmetaUic tubing, a steel sleeve, steel plate, or steel clip
not less than 1.6 mm (1/16 in.) in thickness shaU be used to
protect the cable or tubing.

Exception: A listed and marked steel plate less than 1.6
mm (1/16 in.) thick that provides equal or better protection
against nail or screw penetration shall be permitted.

(C) Cables Through Spaces Behind Panels Designed to
Allow Access. Cables or raceway-type wiring methods,
installed behind panels designed to allow access, shall be
supported according to their appUcable articles.

(D) Cables and Raceways Parallel to Framing Members
and Furring Strips. In both exposed and concealed
locations, where a cable- or raceway-type wiring method is

2010 California Electrical Code

70-127

300.5

ARTICLE 300 - WIRING METHODS

installed parallel to framing members, such as joists,
rafters, or studs, or is installed parallel to furring strips, the
cable or raceway shall be installed and supported so that
the nearest outside surface of the cable or raceway is not
less than 32 mm (VA in.) from the nearest edge of the
framing member or frirring strips where nails or screws are
likely to penetrate. Where this distance cannot be
maintained, the cable or raceway shall be protected from
penetration by nails or screws by a steel plate, sleeve, or
equivalent at least 1.6 mm (1/16 in.) thick.

Exception No. 1 : Steel plates, sleeves, or the equivalent
shall not be required to protect rigid metal conduit,
intermediate metal conduit, rigid nonmetallic conduit, or
electrical metallic tubing.

Exception No. 2: For concealed work in finished
buildings, or finished panels for prefabricated buildings
where such supporting is impracticable, it shall be
permissible to fish the cables between access points.

Exception No. 3: A listed and marked steel plate less than
1.6 mm (1/16 in.) thick that provides equal or better
protection against nail or screw penetration shall be
permitted,

(E) Cables and Raceways Installed IJttder Roof Deckiiig, A

cable- or raceway-type vidring tnethod^ irfetalled in exposi^ C^
concealed locations Mder metalrcormgated sheet roof decking,
shatt be installed and sii$)porteci so :t surface of

the cable or raceway is not less than 38 mm (IH in*) frqm the
nearest surface of theroofdeclangi

FPN: R(X)f deckkig inat^l is often repaired or lepkced afier the
initial raceway or cabling and roofing installation and may be

peaetcated by the^scre^ws ;or o&f .inStolcatd^^ designed, to
provide 'Md down" stiiarigtK o^^^ membrane or

roof iMuiating material i

Exception: Rigid ^^(^l£onduUM[mte}n^ J^^M: £^^dmt

shall no{be required p£om^

(F) Cables and Raceways Installed in ShaUow Grooves.

Cable- or raceway-type wiring methods installed in a groove, to
be covered by wallboard, siding, paneling, carpeting, or similar
finish, shall be protected by 1.6 mm (1/16 in.) thick steel plate,
sleeve, or equivalent or by not less than 32-mm (lV4-in.) free
space for the frill length of the groove in which the cable or
raceway is installed.

Exception No. 1: Steel plates, sleeves, or the equivalent shall
not be required to protect rigid metal conduit, intermediate
metal conduit, rigid nonmetallic conduit, or electrical metallic
tubing.

Exception No. 2: A listed and marked steel plate less than 1,6
mm (1/16 in.) thick that provides equal or better protection
against nail or screw penetration shall be permitted.

(G) Insulated Fittings. Where raceways "pontaki 4 AWG or
larger insulated circuit conductors and these conductors enter a
cabinet, box, enclosure, or raceway, the conductors shall be
protected by a substantial fitting providing a smoothly rounded
insulating surface, unless the conductors are separated from the
fitting or raceway by substantial insulating material that is
securely fastened in place.

Exception: Where threaded hubs or bosses that are an integral
part of a cabinet, box, enclosure, or raceway provide a
smoothly rounded or flared entry for conductors.

Conduit bushings constructed wholly of insulating material
shall not be used to secure a fitting or raceway. The insulating
fitting or insulating material shall have a temperature rating not
less than the insulation temperature rating of the installed
conductors.

300.5 Underground Installations.

(A) Minimum Cover Requirements. Direct-buried cable or
conduit or other raceways shall be mstalled to meet the
minimum cover requirements of Table 300.5. (B) JW^t
Locatiqiis; TTie interior jpf enclosures or r^ewys msta(la|
underground shall be cqrfsidered to be a :wet location; MsiJated
^conductors and cables installed tti these enclosures or raceways
in underground installations shaU be fist^ for j^e m
locafions and siall comjly with 3 1 d8(G).^toy e^^
isplices in an xmderground instaUatioji shallbe apprpve^^
locations'

(D) Protection from Damage. Direct-buried conductors and
cables shall be protected from damage in accordance with
300.5(D)(1) through (D)(4).

(1) Emerging from Grade. Direct-buried conductors and
cables emerging fi-om grade and g)^;^Sin;c^^

Table 300.5 shall be protected by enclosures or raceways
extending from the minimum cover distance below grade
required by 300.5(A) to a point at least 2.5 m (8 ft) above
finished grade. In no case shall the protection be required to
exceed 450 mm (18 in.) below finished grade.

(2) Conductors Entering BuUdings. Conductors entering a
building shall be protected to the point of entrance.

(3) Service Conductors. Underground service conductors
that are not encased in concrete and that are buried 450 mm
(18 in.) or more below grade shall have their location
identified by a warning ribbon that is placed in the trench at
least 300 mm (12 in.) above the underground installafion.

•

70-128

2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.5

Table 300.5 Minimum Cover Requirements, to 600 Volts, Nominal, Burial in Millimeters (Inches)

Type of Wiring Method

or Circuit

Column 1 Direct

Burial Cables or

Conductors

Column 2 Rigid
Metal Conduit
or Intermediate
Metal Conduit

Column 3

Nonmetallic

Raceways

Listed for

Direct Burial

Without

Concrete

Encasement or

Other

Approved

Raceways

Column 4

Residential
Branch Circuits
Rated 120 Volts

or Less with

GFCI Protection

and Maximum

Overcurrent

Protection of 20

Amperes

Column 5

Circuits for

Control of

Irrigation and

Landscape

Lighting Limited

to Not More Than

30 Volts and

Installed with

Type UF or in

Other Identified

Cable or Raceway

Location of Wiring Method or
Circuit

mm in.

All locations not specified below

600 24

150 6

450 18

300 12

150 6

In trench below 50-mm (2 -in.) thick
concrete or equivalent

450 18

150 6

300 12

150 6

Under a building

(in raceway only)

Under minimum of 102 -mm (4-in.)
thick concrete exterior slab with
no vehicular traffic and the slab
extending not less than 152 mm
(6 in.) beyond the underground
installation

450 18

100 4

150 6
(direct burial)
100 4
(in raceway)

Under streets, highways, roads,
alleys, driveways, and parking
lots

600 24

. 600 24

One- and two-family dwelling
driveways and outdoor parking
areas, and used only for dwelling-
related purposes

450 18

300 12

450 18

In or under airport runways,
including adjacent areas where
trespassing prohibited

450 18

Notes:

1. Cover is defined as the shortest distance in millimeters (inches) measured between a point on the top surface of any direct-buried
conductor, cable, conduit, or other raceway and the top surface of finished grade, concrete, or similar cover.

2. Raceways approved for burial only where concrete encased shall require concrete envelope not less than 50 mm (2 in.) thick.

3. Lesser depths shall be permitted where cables and conductors rise for terminations or splices or where access is otherwise required.

4. Where one of the wiring method types listed in Columns 1-3 is used for one of the circuit types in Columns 4 and 5, the shallowest
depth of burial shall be permitted.

5. Where solid rock prevents compliance with the cover depths specified in this table, the wiring shall be installed in metal or nonmetallic
raceway permitted for direct burial. The raceways shall be covered by a minimum of 50 mm (2 in.) of concrete extending down to rock.

2010 Califomia Electrical Code

70-129

300.6

ARTICLE 300 - WIRING METHODS

(4) Enclosure or Raceway Damage. Where the enclosure or
raceway is subject to physical damage, the conductors shall be
installed in rigid metal conduit, intermediate metal conduit,
Schedule 80 f^& conduit, or equivalent.

(E) Splices and Taps. Direct-buried conductors or cables shall
be permitted to be spHced or tapped without the use of spHce
boxes. The splices or taps shall be made in accordance with
110.14(B).

(F) Backfill. Backfill that contains large rocks, paving
materials, cinders, large or sharply angular substances, or
corrosive material shall not be placed in an excavation where
materials may damage raceways, cables, or other substructures
or prevent adequate compaction of fill or contribute to corrosion
of raceways, cables, or other substructures.

Where necessary to prevent physical damage to the
raceway or cable, protection shall be provided in the form of
granular or selected material, suitable running boards, suitable
sleeves, or other approved means.

(G) Raceway Seals. Conduits or raceways through which
moisture may contact Uve parts shall be sealed or plugged at
either or both ends.

FPN: Presence of hazardous gases or vapors may also necessitate
sealing of underground conduits or raceways entering buildings.

(H) Bushing. A bushing, or terminal fitting, with an integral
bushed opening shall be used at the end of a conduit or other
raceway that terminates underground where the conductors or
cables emerge as a direct burial wiring method. A seal
incorporating the physical protection characteristics of a bushing
shall be permitted to be used in lieu of a bushing.

(T) Conductors of the Same Circuit. All conductors of the
same circuit and, where used, the grounded conductor and all
equipment grounding conductors shall be installed in the same
raceway or cable or shall be installed in close proximity in the
same trench.

Exception No. 1: Conductors in parallel in raceways or cables
shall be permitted, but each raceway or cable shall contain all
conductors of the same circuit including egu^fnent grounding
conductors.

Exception No. 2: Isolated phase, polarity, grounded conductor,
and equipment grounding and bonding conductor installations
shall be permitted in nonmetallic raceways or cables with a
nonmetallic covering or nonmagnetic sheath in close proximity
where conductors are paralleled as permitted in 310.4, and
where the conditions of 300.20(B) are met.

(J) Eartb Movement. Where direct-buried conductors,
raceways, or cables are subject to movement by settlement or
firost, direct-buried conductors, raceways, or cables shall be

arranged so as to prevent damage to the enclosed conductors or
to equipment connected to the raceways.

FPN: This section recognizes "S" loops in underground direct
burial to raceway transitions, expansion fittings in raceway risers
to fixed equipment, and, generally, the provision of flexible
connections to equipment subject to settlement or frost heaves.

(K) Directional Boring. Cables or raceways installed using
directional boring equipment shall be approved for the purpose.

300.6 Protection Against Corrosion and Deterioration.

Raceways, cable trays, cablebus, auxiliary gutters, cable armor,
boxes, cable sheathing, cabinets, elbows, couplings, fittings,
supports, and support hardware shall be of materials suitable for
the environment in which they are to be installed.

(A) Ferrous Metal Equipment. Ferrous metal raceways, cable
trays, cablebus, auxiliary gutters, cable armor, boxes, cable
sheathing, cabinets, metal elbows, couplings, nipples, fittings,
supports, and support hardware shall be suitably protected
against corrosion inside and outside (except threads at joints) by
a coating of approved corrosion-resistant material. Where
corrosion protection is necessary and the conduit is threaded in
the field, the threads shall be coated with an approved
electrically conductive, corrosion-resistant compound.

Exception: Stainless steel shall not be required to have
protective coatings.

(1) Protected from Corrosion Solely by Enamel. Where
protected from corrosion solely by enamel, ferrous metal
raceways, cable trays, cablebus, auxihary gutters, cable armor,
boxes, cable sheathing, cabinets, metal elbows, couphngs,
nipples, fittings, supports, and support hardware shall not be
used outdoors or in wet locations as described in 300.6(D).

(2) Organic Coatings on Boxes or Cabinets. Where boxes or

cabinets have an approved system of organic coatings and are
marked "Raintight," "Rainproof," or "Outdoor Type," they shall
be permitted outdoors.

(3) In Concrete or in Direct Contact with the Earth. Ferrous
metal raceways, cable armor, boxes, cable sheathing, cabinets,
elbows, couphngs, nipples, fittings, supports, and support
hardware shall be permitted to be installed in concrete or in
direct contact with the earth, or in areas subject to severe
corrosive influences where made of material approved for the
condition, or where provided with corrosion protection
approved for the condition.

(B) Aluminum Metal Equipment Aluminum raceways, cable
trays, cablebus, auxiliary gutters, cable armor, boxes, cable
sheathing, cabinets, elbows, couplings, nipples, fittings,
supports, and support hardware embedded or encased in
concrete or in direct contact with the earth shall be provided
with supplementary corrosion protection.

70-130

2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.11

(C) Nonmetallic Equipment. Nonmetallic raceways, cable
trays, cablebus, auxiliary gutters, boxes, cables with a
nonmetallic outer jacket and internal metal armor or jacket,
cable sheathing, cabinets, elbows, couplings, nipples, fittings,
supports, and support hardware shall be made of material
approved for the condition and shall comply with (C)(1) and
(C)(2) as appUcable to the specific installation.

(1) Exposed to Sunlight. Where exposed to sunhght, the
materials shall be listed as sunlight resistant or shall be
identified as sunlight resistant.

(2) Chemical Exposure. Where subject to exposure to
chemical solvents, vapors, splashing, or immersion, materials or
coatings shall either be inherently resistant to chemicals based
on their hsting or be identified for the specific chemical reagent.

(D) Indoor Wet Locations. In portions of dairy processing
facilities, laundries, canneries, and other indoor wet locations,
and in locations where walls are frequently washed or where
there are surfaces of absorbent materials, such as damp paper or
wood, the entire wiring system, where installed exposed,
including all boxes, fittings, raceways, and cable used therewith,
shall be mounted so that there is at least a 6-mm (V4-in.) airspace
between it and the wall or supporting surface.

Exception: Nonmetallic raceways, boxes, and fittings shall be
permitted to be installed without the airspace on a concrete,
masonry, tile, or similar surface.

FPN: In general, areas where acids and alkali chemicals are
handled and stored may present such corrosive conditions,
particularly when wet or damp. Severe corrosive conditions may
also be present in portions of meatpacking plants, tanneries, glue
houses, and some stables; in installations immediately adjacent to
a seashore and swimming pool areas; in areas where chemical
deicers are used; and in storage cellars or rooms for hides,
casings, fertilizer, salt, and bulk chemicals.

300.7 Raceways Exposed to Different Temperatures.

(A) Sealing. Where portions of a cable raceway or sleeve are
known to be subjected to different temperatures and where
condensation is known to be a problem, as in cold storage areas
of buildings or where passing from the interior to the exterior of
a building, the raceway or sleeve shall be filled with an
approved material to prevent the circulation of warm air to a
colder section of the raceway or sleeve. An explosionproof seal
shall not be required for this purpose.

(B) Expansion Fittings. Raceways shall be provided with
expansion fittings where necessary to compensate for thermal
expansion and contraction.

FPN: Table 352.44 and ;Tab§fm44 provide the expansion
information for polyvinyl chloride (PVC) M fer rem&C^

|iegn|setog;raJBjond^^^ A nominal

number for steel conduit can be determined by multiplying the
expansion length in ||a|ie;^3||^ by 0.20. The coefficient of
expansion for steel electrical metallic tubing, intermediate metal
conduit, and rigid conduit is (M70; x"loj (0.0000117 mm per
mm of conduit for each °C in temperature change) [S-teO >5 lOj
(0.0000065 in. per inch of conduit for each °F in temperature
change)].

)&3S&: lM;,?P?flB#^^^ ,oE ekpapsioii jfor ahin&um

lefepfticff.Me^c Jibing;, aid ^mimmti^ .filial

boiKii4t &r each m t^mpemtui^ clisp^ P'^O''^' W.

fempemture changeji

300.8 Installation of Conductors with Other Systems.

Raceways or cable trays containing electrical conductors shall
not contain any pipe, tube, or equal for steam, water, air, gas,
drainage, or any service other than electrical.

(JOO.? Jfoiceways to Wet Xocaiioiis Above Grade. Wher3

Igceway^arej^Blled^^ the iiferiol

lof these, raceways shSJ be considered to be a^we^k^^aSoi^
lasplated conductors and cables iiiistalM in p^y^^^S^J^'^i
lobatipnsjafcpvegi^ sM comply with 310,8(C),

300.10 Electrical Continuity of Metal Raceways and
Enclosures. Metal raceways, cable armor, and other metal
enclosures for conductors shall be metallically joined together
into a continuous electrical conductor and shall be connected to
all boxes, fittings, and cabinets so as to provide eflective
electrical continuity. Unless specifically permitted elsewhere in
this Code, raceways and cable assembhes shall be mechanically
secured to boxes, fittings, cabinets, and other enclosures.

Exception No. J: Short sections of raceways used to provide
support or protection of cable assemblies from physical damage
shall not be required to be made electrically continuous.

Exception No. 2: Equipment enclosures to be isolated, as
permitted by 250.96(B), shall not be required to be metallically
joined to the metal raceway.

300.11 Securing and Supporting.

(A) Secured in Place. Raceways, cable assembhes, boxes,
cabinets, and fittings shall be securely fastened in place. Support
wires that do not provide secure support shall not be permitted
as the sole support. Support wires and associated fittings that
provide secure support and that are installed in addition to the
ceiling grid support wires shall be permitted as the sole support.
Where independent support wires are used, they shall be
secured at both ends. Cables and raceways shall not be
supported by ceiling grids.

2010 California Electrical Code

70-131

300.12

ARTICLE 300 - WIRING METHODS

(1) Fire-Rated Assemblies. Wiring located within the cavity of
a fire-rated floor-ceiUng or roof-ceiling assembly shall not be
secured to, or supported by, the ceiling assembly, including the
ceiling support wires. An independent means of secure support
shall be provided and shall be permitted to be attached to the
assembly. Where independent support wires are used, they shall
be distinguishable by color, tagging, or other effective means
firom those that are part of the fire-rated design.

Exception: The ceiling support system shall he permitted to
support wiring and equipment that have been tested as part of
the fire-rated assembly.

FPN: One method of determining fire rating is testing in
accordance with NFPA 251-2006, Standard Methods of Tests of
Fire Resistance of Building Construction and Materials.

(2) Non-Fire-Rated Assemblies. Wiring located within the
cavity of a non-fire-rated floor-ceiling or roof-ceiling assembly
shall not be secured to, or supported by, the ceiling assembly,
including the ceiling support wires. An independent means of
secure support shall be provided and ^feall be permitted to be
attadied to Jie assemb>iy

Exception: The ceiling support system shall be permitted to
support branch-circuit wiring and associated equipment where
installed in accordance with the ceiling system manufacturer's
instructions.

(B) Raceways Used as Means of Support. Raceways shall be
used only as a means of support for other raceways, cables, or
nonelectrical equipment under any of the following conditions:

(1) Where the raceway or means of support is identified for the
piupose

(2) Where the raceway contains power supply conductors for
electrically controlled equipment and is used to support
Class 2 circuit conductors or cables that are solely for the
purpose of connection to the equipment control circuits

(3) Where the raceway is used to support boxes or conduit
bodies in accordance with 314.23 or to support luminaires
in accordance with 410.36(E)

(C) Cables Not Used as Means of Support Cable wiring
methods shall not be used as a means of support for other
cables, raceways, or nonelectrical equipment.

300.12 Mechanical Continuity — Raceways and Cables.

Metal or nonmetallic raceways, cable armors, and cable sheaths
shall be continuous between cabinets, boxes, fittings, or other
enclosures or outlets.

Exception No. 1: Short sections of raceways used to provide
support or protection of cable assemblies from physical damage
shall not be required to be mechanically continuous.

Exception No. 2: yiacmays and cables imtalkd into the bottoni
pf open bottom equipmen^^^ fnopr control

centersj^'andrfioa shall not be

reqUjredjoiem equipment^

300.13 Mechanical and Electrical Continuity —
Conductors.

(A) General, Conductors in raceways shall be continuous
between outiets, boxes, devices, and so forth. There shall be no
spHce or tap within a raceway unless permitted by 300.15;
368.56(A); 376.56; 378.56; 384.56; 386.56; 388.56; or 390.6.

(B) Device Removal, In multiwire branch circuits, the
contmuity of a grounded conductor shall not depend on device
connections such as lampholders, receptacles, and so forth,
where the removal of such devices would interrupt the
continuity.

300.14 Length of Free Conductors at Outlets, Junctions,
and Switch Points. At least 150 mm (6 in.) of fi'ee conductor,
measured fi*om the point in the box where it emerges from its
raceway or cable sheath^ shall be left at each outiet, junction,
and switch point for splices or the connection of luminaires or
devices. Where the opening to an outiet, junction, or switch
point is less than 200 mm (8 in.) in any dimension, each
conductor shall be long enough to extend at least 75 mm (3 in.)
outside the opening.

Exception: Conductors that are not spliced or terminated at the
outlet, junction, or switch point shall not be required to comply
with 300.14.

300.15 Boxes, Conduit Bodies, or Fittings — Where
Required. A box shall be installed at each outlet and switch
point for concealed knob-and-tube wiring.

Fittings and connectors shall be used only with the specific
wiring methods for which they are designed and listed.

Where the wiring method is conduit, tubing, Type AC
cable, Type MC cable. Type MI cable, nonmetallic-sheathed
cable, or other cables, a box or conduit body shall be installed at
each conductor splice point, outlet point, switch point, junction
point, termination point, or pull point, unless otherwise
permitted in 300. 1 5(A) through (M).

(A) Wiring Methods with Interior Access. A box or conduit
body shall not be required for each spUce, junction, switch, pull,
termination, or outlet points in wiring methods with removable
covers, such as wireways, multioutlet assemblies, auxiliary
gutters, and surface raceways. The covers shall be accessible
after installation.

(B) Equipment. An integral junction box or wiring
compartment as part of approved equipment shall be permitted
inheuofabox.

70-132

2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.18

(C) Protection. A box or conduit body shall not be required
where cables enter or exit from conduit or tubing that is used to
provide cable support or protection against physical damage. A
fitting shall be provided on the end(s) of the conduit or tubing to
protect the cable from abrasion.

(D) Type MI Cable. A box or conduit body shall not be
required where accessible fittings are used for straight-through
splices in mineral-insulated metal-sheathed cable.

(E) Integral Enclosure. A wiring device with integral
enclosure identified for the use, having brackets that securely
fasten the device to walls or ceilings of conventional on-site
firame construction, for use with nonmetallic-sheathed cable,
shall be permitted in heu of a box or conduit body.

FPN: See 334.30(C); 545.10; 550.15(1); 551.47(E), Exception
No. 1; and 552.48(E), Exception No. 1.

(F) Fitting. A fitting identified for the use shall be permitted in
Ueu of a box or conduit body where conductors are not sphced
or terminated within the fitting. The fitting shall be accessible
after installation.

(G) Direct-Buried Conductors, As permitted in 300.5(E), a
box or conduit body shall not be required for splices and taps in
direct-buried conductors and cables.

(H) Insulated Devices. As permitted in 334.40(B), a box or
conduit body shall not be required for insulated devices supplied
by nonmetallic-sheathed cable.

(I) Enclosures. A box or conduit body shall not be required
where a splice, switch, terminal, or pull point is in a cabinet or
cutout box, in an enclosure for a switch or overcurrent device as
permitted in 312.8, in a motor controller as permitted in
430.10(A), or in a motor control center.

(J) Luminaires. A box or conduit body shall not be required
where a luminaire is used as a raceway as permitted in 410.64
and 410.65.

(K) Embedded. A box or conduit body shall not be required for
splices where conductors are embedded as permitted in 424.40,
424.41(D), 426.22(B), 426.24(A), and 427.19(A).

(L) Manholes and Handhole Enclosures. A box or conduit
body shall not be required for conductors in manholes or
handhole enclosures, except where connecting to electrical
equipment. The installation shall comply with the provisions of
Part V of Article 110 for manholes, and 314.30 for handhole
enclosures.

(M) Closed Loop. A box shall not be required with a closed-
loop power distribution system where a device identified and
listed as suitable for installation without a box is used.

300.16 Raceway or Cable to Open or Concealed Wiring.

(A) Box, jC?oAdpft:Bp#i'.^^^^^^^ A box, condifit bod)?, or

terminal fitting having a separately bushed hole for each
conductor shall be used wherever a change is made from
conduit, electrical metallic tubing, electrical nonmetallic tubing,
nonmetallic-sheathed cable. Type AC cable, Type MC cable, or
mineral-insulated, metal-sheathed cable and surface raceway
wiring to open wiring or to concealed knob-and-tube wiring. A
fitting used for this purpose shall contain no taps or splices and
shall not be used at luminaire outiets. ^j^coadiit bojiy jased for
i€^ :shaU cotklam ao taps or splices, unless itpoirtplS

(B) Bushing. A bushing shall be permitted in Heu of a b(3x or

terminal where the conductors emerge from a raceway and enter
or terminate at equipment, such as open switchboards,
unenclosed control equipment, or similar equipment. The
bushing shall be of the insulating type for otiier than lead-
sheathed conductors.

300.17 Number and Size of Conductors in Raceway. The

number and size of conductors in any raceway shall not be more
than will permit dissipation of tiie heat and ready installation or
withdrawal of the conductors without damage to the conductors
or to their insulation.

FPN: See the following sections of this Code: intermediate metal
conduit, 342.22; rigid metal conduit, 344.22; flexible metal
conduit, 348.22; liquidtight flexible metal conduit, 350.22; ^yC
conduit, 352.22; MJM-'<SS^~'JB^; \]l^iJM^:^MsM;
liquidtight nonmetallic flexible conduit, 356.22; electrical
metallic tubing, 358.22; flexible metallic tubing, 360.22;
electrical nonmetallic tubing, 362.22; cellular concrete floor
raceways, 372.11; cellular metal floor raceways, 374.5; metal
wireways, 376.22; nonmetallic wireways, 378.22; surface metal
raceways, 386.22; surface nonmetallic raceways, 388.22;
underfloor raceways, 390.5; fixture wire, 402.7; theaters, 520.6;
signs, 600.31(C); elevators, 620.33; audio signal processing,
amplification, and reproduction equipment, 640.23(A) and
640.24; Class 1, Class 2, and Class 3 circuits. Article 725; fire
alarm circuits, Article 760; and optical fiber cables and raceways,
Article 770.

300. IS Raceway Installations.

(A) Complete Runs. Raceways, otiier tiian busways or exposed
raceways having hinged or removable covers, shall be installed
complete between outlet, junction, or splicing points prior to the
installation of conductors. Where required to facilitate the
installation of utilization equipment, the raceway shall be
permitted to be initially installed v^thout a terminating
connection at tiie equipment. Prev^ed raceway assembhes shall
be permitted only where specifically permitted in this Code for
the applicable wiring method.

2010 California Electrical Code

70-133

300.19

ARTICLE 300 - WIRING METHODS

Exception: Short sections of raceways used to contain
conductors or cable assemblies for protection from physical
damage shall not be required to be installed complete
between outlet, junction, or splicing points.

(B) Welding. Metal raceways shall not be supported,
terminated, or connected by welding to the raceway unless
specifically designed to be or otherwise specifically permitted to
be in this Code.

300.19 Supporting Conductors in Vertical Raceways.

(A) Spacing Intervals — Maximum. Conductors in vertical
raceways shall be supported if the vertical rise exceeds the
values in Table 300.19(A). One cable support shall be provided
at the top of the vertical raceway or as close to the top as
practical. Intermediate supports shall be provided as necessary
to limit supported conductor lengths to not greater than those
values specified in Table 300.19(A).

Exception: Steel wire armor cable shall be supported at the top
of the riser with a cable support that clamps the steel wire
armor. A safety device shall be permitted at the lower end of the
riser to hold the cable in the event there is slippage of the cable
in the wire-armored cable support. Additional wedge-type
supports shall be permitted to relieve the strain on the
equipment terminals caused by expansion of the cable under
load.

5(JS) Fire-Rated Cables and Coiiductprs. Support methods
Wd spacing intervals for fire-rated cables and conductors
Ishall comply with any restrictions provided in the listing of
the electrical circuit protective system used and in no case
|hatl exceed lif! vaiues^in T^

Table 300.19(A) Spacings for Conductor Supports

(1) By clamping devices constructed of or employing
insulating wedges inserted in the ends of the raceways.
Where clamping of insulation does not adequately
support the cable, the conductor also shall be clamped.

(2) By inserting boxes at the required intervals in which
insulating supports are installed and secured in a
satisfactory manner to withstand the weight of the
conductors attached thereto, the boxes being provided
with covers.

(3) Injunction boxes, by deflecting the cables not less than
90 degrees and carrying them horizontally to a
distance not less than twice the diameter of the cable,
the cables being carried on two or more insulating
supports and additionally secured thereto by tie wires
if desired. Where this method is used, cables shall be
supported at intervals not greater than 20 percent of
those mentioned in the preceding tabulation.

(4) By a method of equal effectiveness.

300.20 Induced Currents in ferrous Metal Enclosures
or F^rrbu^ Metal Raceways.

(A) Conductors Grouped Together. Where conductors
carrying alternating current are installed in ferrous metal
enclosures or ^ferrous metal raceways, they shall be arranged
so as to avoid heating the surrounding ferrous metal by
induction. To accomphsh this, all phase conductors and,
where used, the grounded conductor and all equipment
grounding conductors shall be grouped together.

Exception No. 1: Equipment grounding conductors for
certain existing installations shall be permitted to be
installed separate from their associated circuit conductors
where run in accordance with the provisions of 250.130(C).

Conductors

Aluminum

or Copper-Clad

Support of Conductors in

Aluminum

Copper

Size of Wire

Vertical Raceways

18 AWG through 8 AWG

Not greater than

100

6AWGthroughl/0AWG

Not greater than

200

100

2/0 AWG through 4/0 AWG

Not greater than

180

Over 4/0 AWG through 350 kcmil

Not greater than

135

Over 350 kcmil through 500 kcmil

Not greater than

120

Over 500 kcmil through 750 kcmil

Not greater than

Over 750 kcmil

Not greater than

70-134

2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.22

Exception No. 2: A single conductor shall be permitted to
he installed in a ferromagnetic enclosure and used for skin-
effect heating in accordance with the provisions of 426.42
and 427.47.

(B) Individual Conductors. Where a single conductor
carrying alternating current passes through metal with
magnetic properties, the inductive effect shall be
minimized by (1) cutting slots in the metal between the
individual holes through which the individual conductors
pass or (2) passing all the conductors in the circuit through
an insulating wall sufficiently large for all of the
conductors of the circuit.

Exception: In the case of circuits supplying vacuum or electric-
discharge lighting systems or signs or X-ray apparatus, the
currents carried by the conductors are so small that the
inductive heating effect can be ignored where these conductors
are placed in metal enclosures or pass through metal

FPN: Because aluminum is not a magnetic metal, there will
be no heating due to hysteresis; however, induced currents
will be present. They will not be of sufficient magnitude to
require grouping of conductors or special treatment in
passing conductors through aluminum wall sections.

300.21 Spread of Fire or Products of Combustion.

Electrical installations in hollow spaces, vertical shafts, and
ventilation or air-handling ducts shall be made so that the
possible spread of fire or products of combustion will not
be substantially increased. Openings around electrical
penetrations through fire-resistant-rated walls, partitions,
floors, or ceilings shall be firestopped using approved
methods to maintain the fire resistance rating.

FPN: Directories of electrical construction materials
published by qualified testing laboratories contain many
listing installation restrictions necessary to maintain the fire-
resistive rating of assemblies where penetrations or openings
are made. Building codes also contain restrictions on
membrane penetrations on opposite sides of a fire-resistance-
rated wall assembly. An example is the 600-mm (24-in.)
minimum horizontal separation that usually applies between
boxes installed on opposite sides of the wall. Assistance in
complying with 300.21 can be found in building codes, fire
resistance directories, and product listings.

300.22 Wiring in Ducts, Plenums, and Other Air-
Handling Spaces. The provisions of this section apply to
the installation and uses of electrical wiring and equipment
in ducts, plenums, and other air-handling spaces.

FPN: See Article 424, Part VI, for duct heaters.

(A) Ducts for Dust, Loose Stock, or Vapor Removal. No

wiring systems of any t3^e shall be installed in ducts used
to transport dust, loose stock, or flammable vapors. No
wiring system of any type shall be installed in any duct, or
shaft containing only such ducts, used for vapor removal or
for ventilation of commercial-type cooking equipment.

(B) Ducts or Plenums Used for Environmental Air. Only
wiring methods consisting of Type MI cable, Type MC

cable employing a smooth or corrugated impervious metal
sheath without an overall nonmetallic covering, electrical
metallic tubing, flexible metaUic tubing, intermediate metal
conduit, or rigid metal conduit without an overall
nonmetallic covering shall be installed in ducts or plenums
specifically fabricated to transport environmental air.
Flexible metal conduit shall be permitted, in lengths not to
exceed 1.2 m (4 ft), to connect physically adjustable
equipment and devices permitted to be in these ducts and
plenum chambers. The connectors used with flexible metal
conduit shall effectively close any openings in the
connection. Equipment and devices shall be permitted
within such ducts or plenum chambers only if necessary for
their direct action upon, or sensing of, the contained air.
Where equipment or devices are installed and illumination
is necessary to facilitate maintenance and repair, enclosed
gasketed-type luminaires shall be permitted.

(C) Other Space Used for Environmental Air. This
section applies to space used for environmental air-
handling purposes other than ducts and plenums as
specified in 300.22(A) and (B). It does not include
habitable rooms or areas of buildings, the prime purpose of
which is not air handling.

FPN: The space over a hung ceiling used for environmental
air-handling purposes is an example of the type of other
space to which this section applies.

Exception: This section shall not apply to the joist or stud
spaces of dwelling units where the wiring passes through such
spaces perpendicular to the long dimension of such spaces.

(1) Wiring Methods. The wiring methods for such other
space shall be Hmited to totally enclosed, nonventilated,
insulated busway having no provisions for plug-in
connections. Type MI cable. Type MC cable without an
overall nonmetallic covering. Type AC cable, or other
factory-assembled muhiconductor control or power cable
that is specifically listed for the use, or listed prefabricated
cable assemblies of metallic manufactured wiring systems
without nonmetallic sheath. Other types of cables,
conductors, jaiid. raceways shall be permitted. to be installed
in electrical metallic tubing, flexible metallic tubing,
intermediate metal conduit, rigid metal conduit without an
overall nonmetallic covering, flexible metal conduit, or,
where accessible, surface metal raceway or metal wireway
with metal covers or solid bottom metal cable tray with
soHd metal covers.

(2) Equipment. Electrical equipment with a metal
enclosure, or with a nonmetallic enclosure listed for the use
and having adequate fire-resistant and low-smoke-
producing characteristics, and associated wiring material
suitable for the ambient temperature shall be permitted to
be installed in such other space unless prohibited elsewhere
in this Code.

Exception: Integral fan systems shall be permitted where
specifically identified for such use.

2010 California Electrical Code

70-135

300.23

ARTICLE 300 - WIRING METHODS

(D) Information Technology Equipment. Electrical
wiring in air-handling areas beneath raised floors for
information technology equipment shall be permitted in
accordance with Article 645.

300.23 Panels Designed to Allow Access. Cables,
raceways, and equipment installed behind panels designed
to allow access, including suspended ceiling panels, shall
be arranged and secured so as to allow the removal of
panels and access to the equipment.

IL Requirements for over 600 Volts, Nominal

300.31 -Covers Required. Suitable covers shall be
installed on all boxes, fittings, and similar enclosures to
prevent accidental contact with energized parts or physical
damage to parts or insulation.

300.32 Conductors of Different Systems. See

300.3(C)(2).

300.34 Conductor Bending Radius. The conductor shall
not be bent to a radius less than 8 times the overall
diameter for nonshielded conductors or 12 times the overall
diameter for shielded or lead-covered conductors during or
after installation. For multiconductor or multiplexed single-
conductor cables having individually shielded conductors,
the minimum bending radius is 12 times the diameter of the
individually shielded conductors or 7 times the overall
diameter, whichever is greater.

300.35 Protection Against Induction Heating. Metallic
raceways and associated conductors shall be arranged so as
to avoid heating of the raceway in accordance with the
applicable provisions of 300.20.

300.37 Aboveground Wiring Methods. Aboveground
conductors shall be installed in rigid metal conduit, in
intermediate metal conduit, in electrical metallic tubing, in
rigid nonmetallic conduit, in cable trays, as busways, as
cablebus, in other identified raceways, or as exposed runs
of metal-clad cable suitable for the use and purpose. In
locations accessible to qualified persons only, exposed runs
of Type MV cables, bare conductors, and bare busbars
shall also be permitted. Busbars shall be permitted to be
either copper or aluminum.

300.39 Braid-Covered Insulated Conductors —
Exposed Installation. Exposed runs of braid-covered
insulated conductors shall have a flame-retardant braid. If
the conductors used do not have this protection, a flame-
retardant saturant shall be applied to the braid covering
after installation. This treated braid covering shall be
stripped back a safe distance at conductor terminals,
according to the operating voltage. Where practicable, this
distance shall not be less than 25 mm (1 in.) for each
kilovoh of the conductor-to-ground voltage of the circuit.

300.40 Insulation Shielding. MetaUic and

semiconducting insulation shielding components of
shielded cables shall be removed for a distance dependent
on the circuit voltage and insulation. Stress reduction
means shall be provided at all terminations of factory-
applied shielding.

Metallic shielding components such as tapes, wires, or
braid^ or (^mbinad (his_ thereof, ^all^Jb^ to a

grounding, cd]Suctor, grounding busbar,:or a grounding
ielectrode.

300.42 Moisture or Mechanical Protection for Metal-
Sheathed Cables. Where cable conductors emerge from a
metal sheath and where protection against moisture or
physical damage is necessary, the insulation of the
conductors shall be protected by a cable sheath terminating
device.

300.50 Underground Installations.

(A) General. Underground conductors shall be identified
for the voltage and conditions under which they are
installed. Direct burial cables shall comply with the
provisions of 310.7. Underground cables shall be installed
in accordance with 300.50(A)(1) or (A)(2), and the
installation shall meet the depth requirements of Table
300.50.

(1) Shielded Cables and Nonshielded Cables in Metal-
Sheathed Cable Assemblies. Underground cables,
including nonshielded, Type MC and moisture-impervious
metal sheath cables, shall have those sheaths grounded
through an effective grounding path meeting the
requirements of 250.4(A)(5) or (B)(4). They shall be direct
buried or installed in raceways identified for the use.

(2) Other Nonshielded Cables. Other nonshielded cables
not covered in 300.50(A)(1) shall be installed in rigid metal
conduit, intermediate metal conduit, or rigid nonmetallic
conduit encased in not less than 75 mm (3 in.) of concrete.

(B) Protection from Damage. Conductors emerging from
the ground shall be enclosed in listed raceways. Raceways
installed on poles shall be of rigid metal conduit,
intermediate metal conduit. Schedule 80 jP VC conduit, or
equivalent, extending from the minimum cover depth
specified in Table 300.50 to a point 2.5 m (8 ft) above
finished grade. Conductors entering a building shall be
protected by an approved enclosure or raceway from the
minimum cover depth to the point of entrance. Where
direct-buried conductors, raceways, or cables are subject to
movement by settlement or frost, they shall be installed to
prevent damage to the enclosed conductors or to the
equipment connected to the raceways. Metallic enclosures
shall be grounded.

70-136

2010 California Electrical Code

ARTICLE 300 - WIRING METHODS

300.50

Table 300.50 Minimum Co vera Requirements

General Conditions (not otherwise specified)

Special Conditions (use if applicable)

(1)

Direct-Buried

Cables

(2)

Rigid

Non metallic

Conduit^

(3)

Rigid Metal

Conduit and

Intermediate

Metal Conduit

(4)

Raceways under

buildings or

exterior concrete

slabs, 100 mm

(4 in.) minimum
thickness^

(5)

Cables in airport

runways or

adjacent areas

where trespass is

prohibited

(6)

Areas subject
to vehicular

traffic, such as

thoroughfares

and

commercial

parking areas

Circuit Voltage

in.

Over 600 V

through 22 kV

750

450

150

100

450

600

Over 22 kV

through 40 kV

900

600

150

100

450

600

Over 40 kV

1000

42 ^

750

150

100

450

600

General Notes:

1 . Lesser depths shall be permitted where cables and conductors rise for terminations or splices or where access is otherwise required.

2. Where solid rock prevents compliance with the cover depths specified in this table, the wiring shall be installed in a metal or nonmetallic
raceway permitted for direct burial. The raceways shall be covered by a minimum of 50 mm (2 in.) of concrete extending down to rock.

jfeVmrnijium^co^ ISd

mm (6 ia|fbteacji^5^ (2 m*} of conwt^iot equiyai^t placed entirely within the ^ei]K^k oyer the underground installatioB.

Specific Footnotes:

a Cover is defined as the shortest distance in millimeters (inches) measured between a point on the top surface of any direct-buried
conductor, cable, conduit, or other raceway and the top surface of finished grade, concrete, or similar cover.

b Listed by a qualified testing agency as suitable for direct burial without encasement. All other nonmetallic systems shall require 50 mm
(2 in.) of concrete or equivalent above conduit in addition to the table depth.

c The slab shall extend a minimum of 150 mm (6 in.) beyond the underground installation, and a warning ribbon or other effective means
suitable for the conditions shall be placed above the underground installation.

P JJt^^md d3Jeot"bu0ed^mblg...lfaat..afe gpt '^i£^|g4 <^^^tpci^^y^^gj^cm^m4 ,^.M4# l§9JMBlW,MdM. MPJfe,b^fe>w;,^^e shalj
E£ye thei| lOcai&dn ideMfied b^a warning ribboB Jhatjs placed iti the, ti^ndi ht least 3M??ilCl^JiAi&^.S^.i^M?li

(C) Splices. Direct burial cables shall be permitted to be
spliced or tapped v^ithout the use of splice boxes, provided
they are installed using materials suitable for the
application. The taps and splices shall be watertight and
protected from mechanical damage. Where cables are
shielded, the shielding shall be continuous across the splice
or tap.

Exception: At splices of an engineered cabling system,
metallic shields of direct-buried single-conductor cables
with maintained spacing between phases shall be permitted
to be interrupted and overlapped. Where shields are
interrupted and overlapped, each shield section shall be
grounded at one point.

(D) Backfill. Backfill containing large rocks, paving
materials, cinders, large or sharply angular substances, or
corrosive materials shall not be placed in an excavation
where materials can damage or contribute to the corrosion
of raceways, cables, or other substructures or where it may
prevent adequate compaction of fill.

Protection in the form of granular or selected material
or suitable sleeves shall be provided to prevent physical
damage to the raceway or cable.

(E) Raceway Seal. Where a raceway enters from an
underground system, the end within the building shall be
sealed with an identified compound so as to prevent the
entrance of moisture or gases, or it shall be so arranged to
prevent moisture from contacting live parts.

2010 California Electrical Code

70-137

310.1

ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING

ARTieLE310

Conductors fdr General Wiring

310.1 Scope. This article covers general requirements for
conductors and their type designations, insulations,
markings, mechanical strengths, ampacity ratings, and uses.
These requirements do not apply to conductors that form an
integral part of equipment, such as motors, motor
controllers, and similar equipment, or to conductors
specifically provided for elsewhere in this Code.

FPN: For flexible cords and cables, see Article 400. For
fixture wires, see Article 402.

310.2 Conductors.

(A) Insulated. Conductors shall be insulated.

Exception: Where covered or bare conductors are
specifically permitted elsewhere in this Code,

FPN: See 250.184 for insulation of neutral conductors of a
solidly grounded high-voltage system.

(B) Conductor Material. Conductors in this article shall
be of aluminum, copper-clad aluminum, or copper unless
otherwise specified.

310.3 Stranded Conductors. Where installed in
raceways, conductors of size 8 AWG and larger shall be
stranded.

Exception: As permitted or required elsewhere in this Code.

310.4 Conductors in Parallel.

(A) Generail. Aluminum, copper-clad aluminum, or copper
conductors of size 1/0 AWG and larger, comprising each
phase, polarity, neutral, or grounded circuit conductor shall
be permitted to be connected in parallel (electrically joined
at both ends).

Exception No. 1: Conductors in sizes smaller than 1/0
A WG shall be permitted to be run in parallel to supply
control power to indicating instruments, contactors, relay^s,
solenoids, and similar control devices, or for frequencies of
360 Hz and higher, provided all of the following apply:

(a) They are contained within the same raceway or
cable.

(b) The ampacity of each individual conductor is
sufficient to carry the entire load current shared by the
parallel conductors.

(c) The overcurrent protection is such that the
ampacity of each individual conductor will not be exceeded
if one or more of the parallel conductors become
inadvertently disconnected.

Exception No. 2: Under engineering supervision,
grounded neutral conductors in sizes 2 AWG and larger
shall be permitted to be run in parallel for existing
installations.

FPN te JBkception;;JS Exception No. 2 can be used to
alleviate overheating of neutral conductors in existing
installations due to high content of triplen harmonic currents.

(B) Conductor Characterislics. The paralleled conductors
in each phase, polarity, neutral, grounded circuit conductor,
or equipment gro^inding^cOIld^ictor shall comply with all of
the following:

(1) Be the same length

(2) Have the same conductor material

(3) Be the same size in circular mil area

(4) Have the same insulation type

(5) Be terminated in the same manner

(C) Separata Cables oi^ Raceways. Where run in separate
cables^or raceways, the |ables or raceways with conductors
shall have the same htAber of coEductots an^^

the]; same, elecfical^ Conductors of one

phase, jpolarity, neutral, grourided circuit conductor, or
aqtiipment groundiag^^^c^^ shall not be required to

have the same physical characteristics as those of another
phase, polarity, neutral, grounded circuit conductor, or
equipment grounding co'pd^^ to achieve balance.

@); Anyyaeji^ Conductors installed in parallel

shall comply with the provisions of 3 10.15(B)(2)(a).

(Ej JEqiiipment Grouiipiiig Conductors, Where parallel
equipment grounding cbEductors are usdd, they shall be
sized in accordance with 250 J 22. Sectioned equipment
groua4ing conductors smaller than 1/0 AWG shall be
permitted in multic0n4uctor cables in accordance; with
3 10. 1 3 i provided the combined circular mil area in each
g^fe cbmplies ^

310.5 Minimum Size of Conductors. The minimum size
of conductors shall be as shown in Table 310.5, except as
permitted elsewhere in this Code.

Table 310.5 Minimum Size of Conductors

Conductor Voltage
Rating (Volts)

Minimum Conductor Size (AWG)

Copper

Aluminum or

Copper-Clad

Aluminum

0-2000

2001-8000

8001-15,000

15,001-28,000

28,001-35,000

14
8
2
1
1/0

12
8
2
1
1/0

•

70-138

2010 California Electrical Code

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

310.11

310.6 Shielding. Solid dielectric insulated conductors
operated above 2000 volts in permanent installations shall
have ozone-resistant insulation and shall be shielded. All
metallic^ insulation shields^shall J)e_jb<)niiiected ib^^
grounding^elcGtrbde eonHuctor, j^oundi^^^ Or g
grounding elecfa^ode, Shielding shall be for the purpose of
confining the voltage stresses to the insulation.

Exception No. 1 : Nonshielded insulated conductors listed
by a qualified testing laboratory shall be permitted for use
up to 2400 volts under the following conditions:

(a) Conductors shall have insulation resistant to
electric discharge and surface tracking, or the insulated
conductor(s) shall be covered with a material resistant to
ozone, electric discharge, and surface tracking.

(b) Where used in wet locations, the insulated
conductor(s) shall have an overall nonmetallic jacket or a
continuous metallic sheath.

EXceptionWo<2jj Where permitted in 310. 7, ^§xceptiqn Na^i

310.7 Direct-Burial Conductors. Conductors used for direct-
burial applications shall be of a type identified for such use.

Cables rated above 2000 volts shall be shielded.

Exception No. 1: Nonshielded multiconductor cables rated
2001-2400 volts shall be permitted if the cable has an
overall metallic sheath or armor.

The metaUic shield, sheath, or armor shall be

jpomiectei#-'-a:^utii<^^

Exception No. 2:^ 4irfi^<i;i^^Mi^

'pfmU$:-i^PS^e 'mted-tip-- to SOWvdlis -imi^ 'ar^-pm^iifpd^lyy^

FPN No. 1: See 300.5 for installation requirements for
conductors rated 600 volts or less.

FPN No. 2: See 300.50 for installation requirements for
conductors rated over 600 volts.

310.8 Locations.

(A) Dry Locations. Insulated conductors and cables used in
dry locations shall be any of the types identified in this Code.

(B) Dry and Damp Locations. Insulated conductors and
cables used in dry and damp locations shall be Types PEP,
FEPB, MTW, PFA, RHH, RHW, RHW-2, SA, THHN,
THW, THW-2, THHW, THWN, THWN-2, TW, XHH,
XHHW, XHHW-2, Z, or ZW.

(1) Be moisture-impervious metal-sheathed

(2) Be types MTW, RHW, RHW-2, TW, THW, THW-2,
THHW, THWN, THWN-2, XHHW, XHHW-2, ZW

(3) Be of a type listed for use in wet locations

(D) Locations Exposed to Direct Sunlight. Insulated
conductors or cables used where exposed to direct rays of
the sun shall comply with (0)(1) or 03X2):

(1) Conductors and cables shall be listed, or listed and
marked, as being sunlight resistant

(2) Conduptors and cables shaUbg covered with insulating
material, such as tape or sleeving, that is listed, or
listed and marked, as being sunlight resistant

310.9 Corrosive Conditions. Conductors exposed to oils,
greases, vapors, gases, fumes, liquids, or other substances
having a deleterious effect on the conductor or insulation
shall be of a type suitable for the application.

310.10 Temperature Limitation of Conductors. No

conductor shall be used in such a manner that its operating
temperature exceeds that designated for the type of insulated
conductor involved. In no case shall conductors be associated
together in such a way, with respect to type of circuit, the
wiring method employed, or the nxunber of conductors, that
the limiting temperature of any conductor is exceeded.

FPN: The temperature rating of a conductor [see Table
3IM1S and labie^lllglllg)! is the maximum
temperature, at any location along its length, that the
conductor can withstand over a prolonged time period
without serious degradation. The allowable ampacity tables,
the ampacity tables of Article 310 and the ampacity tables
of Annex B, the correction factors at the bottom of these
tables, and the notes to the tables provide guidance for
coordinating conductor sizes, types, allowable ampacities,
ampacities, ambient temperatures, and number of associated
conductors.

The principal determinants of operating
temperature are as follows:

(1) Ambient temperature — ambient temperature may vary
along the conductor length as well as from time to
time.

(2) Heat generated internally in the conductor as the result
of load current flow, including fundamental and
harmonic currents.

(3) The rate at which generated heat dissipates into the
ambient medium. Thermal insulation that covers or
surrounds conductors affects the rate of heat
dissipation,

(4) Adjacent load-carrying conductors — adjacent
conductors have the dual effect of raising the ambient
temperature, and impeding heat dissipation.

310.11 Marking.

(A) Required Information. All conductors and cables
shall be marked to indicate the following information,
using the applicable method described in 310.11(B):

2010 California Electrical Code

70-139

310.12

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

(1) The maximum rated voltage.

(2) The proper type letter or letters for the type of wire or
cable as specified elsewhere in this Code.

(3) The manufacturer's ' name, trademark, or other
distinctive marking by which the organization
responsible for the product can be readily identified.

(4) The AWG size or circular mil area.

FPN: See Conductor Properties, Table 8 of Chapter 9, for
conductor area expressed in SI units for conductor sizes
specified in AWG or circular mil area.

(5) Cable assemblies where the neutral conductor is smaller
than the ungrounded conductors shall be so marked.

(B) Method of Marking.

(1) Surface Marking. The following conductors and
cables shall be durably marked on the surface. The AWG
size or circular mil area shall be repeated at intervals not
exceeding 610 mm (24 in.). All other markings shall be
repeated at intervals not exceeding 1.0 m (40 in.).

(1) Single-conductor and multiconductor rubber- and
thermoplastic-insulated wire and cable

(2) NonmetaUic-sheathed cable

(3) Service-entrance cable

(4) Underground feeder and branch-circuit cable

(5) Tray cable

(6) Irrigation cable

(7) Power-limited tray cable

(8) Instrumentation tray cable

(2) Marker Tape. Metal-covered multiconductor cables
shall employ a marker tape located within the cable and
running for its complete length.

Exception No. I: Mineral-insulated, metal-sheathed cable.

Exception No. 2: Type AC cable.

Exception No. 3: The information required in 310.11(A)
shall be permitted to be durably marked on the outer
nonmetallic covering of Type MC, Type ITC, or Type PLTC
cables at intervals not exceeding 1.0 m (40 in.).

Exception No. 4: The information required in 310.11(A)
shall be permitted to be durably marked on a nonmetallic
covering under the metallic sheath of Type ITC or Type
PLTC cable at intervals not exceeding 1.0 m (40 in.).

FPN: Included in the group of metal-covered cables are
Type AC cable (Article 320), Type MC cable (Article 330),
and lead-sheathed cable.

(3) Tag Marking. The following conductors and cables
shall be marked by means of a printed tag attached to the
coil, reel, or carton:

(1) Mineral-insulated, metal-sheathed cable

(2) Switchboard wires

(3) Metal-covered, single-conductor cables

(4) Type AC cable

(4) Optional Marking of Wire Size. The information
required in 310.11(A)(4) shall be permitted to be marked
on the surface of the individual insulated conductors for the
following multiconductor cables:

(1) Type MC cable

(2) Tray cable

(3) Irrigation cable

(4) Power-limited tray cable

(5) Power-limited fire alarm cable

(6) Instrumentation tray cable

(C) Suffixes to Designate Number of Conductors. A type
letter or letters used alone shall indicate a single insulated
conductor. The letter suffixes shall be indicated as follows:

(1) D — For two insulated conductors laid parallel within
an outer nonmetallic covering

(2) M — For an assembly of two or more insulated conductors
twisted spirally within an outer nonmetallic covering

(D) Optional Markings. All conductors and cables
contained in Chapter 3 shall be permitted to be surface
marked to indicate special characteristics of the cable
materials. These markings include, but are not limited to,
markings for limited smoke, sunlight resistant, and so forth.

310.12 Conductor Identification.

(A) Grounded Conductors. Insulated or covered
grounded conductors shall be identified in accordance with
200.6.

(B) Equipment Grounding Conductors. Equipment
grounding conductors shall be in accordance with 250.119.

(C) Ungrounded Conductors. Conductors that are
intended for use as ungrounded conductors, whether used
as a single conductor or in multiconductor cables, shall be
finished to be clearly distinguishable from grounded and
grounding conductors. Distinguishing markings shall not
conflict in any manner with the surface markings required
by 310.11(B)(1). Branch-circuit ungrounded conductors
shall be identified in accordance with 210.5(C). Feeders
shall be idendfied in accordance with 215.12.

Exception: Conductor identification shall be permitted in
accordance with 200. 7.

310.13 Conductor Constructions and Applications.

Insulated conductors shall comply with the applicable
provisions of Table 310.13^tjwughtabie3;^^

•

70-140

2010 California Electrical Code

ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING

310.13

These conductors shall be permitted for use in any of
the wiring methods recognized in Chapter 3 and as speci-
fied in their respective tables or as permitted elsewhere in
this Code.

FPN: Thermoplastic insulation may stiffen at temperatures
lower than -10°C (+14°F). Thermoplastic insulation may
also be deformed at normal temperatures where subjected

to pressure, such as at points of support. Thermoplastic
insulation, where used on dc circuits in wet locations, may
result in electroendosmosis between conductor and
insulation.

Equipment grounding conductors shall be permitted to
be sectioned within a listed mnlticpnductor cable, provided
the -combined circular ml^^^ complies with 250422.

Table 310.13(A) Conductor Applications and Insulations Rated 600 Volts

Tiiickness of Insulation

Maximum Operating

Trade Name

Type Letter

Temperature

Application Provisions

Insulation

AWG or kcmil

mils

Outer Covering^

Fluorinated

FEPor

90°C

Dry and damp locations

Fluorinated ethylene

14-10

0.51

None

ethylene

FEPB

194°F

propylene

8-2

0.76

propylene

200°C
392°F

Dry locations — special
applications^

Fluorinated ethylene
propylene

14-8

0.36

Glass braid

6-2

0.36

Glass or other suitable
braid material

Mineral insulation

90X

Dry and wet locations

Magnesium oxide

18-16^

0.58

Copper or alloy steel

(metal sheathed)

194°F

16-10

0.91

250X

For special applications'^

9-4

1.27

482°F

3-500

1.40

Moisture-, heat-,

MTW

60°C

Machine tool wiring in

Flame-retardant

(A)

(A) None

and oil-resistant

140°F

wet locations

moisture-, heat-, and
oil-resistant

(B) Nylon jacket or

thermoplastic

equivalent

90X

Machine tool wiring in

thermoplastic

22-12

0.76

194°F

dry locations.
FPN: See NFPA 79.

4-2

1-^/0

213-500

501-1000

0.76
1.14
1.52
1.52
2.03
241
2.79

30
45
60
60
80
95
110

Paper

85°C
185T

For underground service
conductors, or by special
permission

Paper

Lead sheath

Perfluoro-alkoxy

PFA

90°C
194°F

Dry and damp locations

Perfluoro-alkoxy

14-10
8-2

0.51
0,76

20
30

None

200°C

Dry locations — special

1^/0

1.14

392°F

applications^

Perfluoro-alkoxy

PFAH

250''C

Dry locations only. Only

Perfluoro-alkoxy

14-10

0.51

None

482°F

for leads within apparatus
or within raceways
connected to apparatus
(nickel or nickel-coated
copper only)

8-2
I^/O

0.76
1.14

Thermoset

RHH

90"C

Dry and damp locations

14-10

1.14

Moisture-resistant,

•

194°F

8-2

1-1/0

213-500

501-1000

1001-2000

1.52
2.03
241
2.79
3.18

60
80
95
110
125

flame-retardant,
nonmetallic covering'

Moisture-

RHW^

75°C

Dry and wet locations

Flame-retardant,

14-10

1.14

Moisture-resistant,

resistant

167°F

moisture-

8-2

1.52

flame-retardant,

thermoset

resistant thermoset

I^/O

2 03

nonmetallic coveringi

RHW-2

90^*0

213-500

2.41

}94,T

501-1000

2.79

110

1001-2000

3.18

125

Silicone

90°C

Dry and damp locations

Silicone rubber

14-10

1.14

Glass or other suitable

194°F

8-2
1-4/0

1.52
2.03

60
80

braid material

200T

For special application^

213-500

241

392°F

501-1000
1001-2000

2.79
3.18

110

125

(Continues)

2010 California Electrical Code

70-141

310.13

ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING

Table 310.13(A) Continued

Thickness of Insulation

Maximum Operating

Trade Name

T^pe Letter

Temperature

Application Provisions

Insulation

AWG or kcmil

mils

Outer Covering*

Thermoset

SIS

90°C

Switchboard wiring only

Flame-retardant

14-10

0.76

None

194°F

thermoset

8-2
1^/0

1.14
2.41

Thennoplastic and

TBS

90°C

Switchboard wiring only

Thermoplastic

14-10

0.76

Flame-retardant,

fibrous outer

194°F

1.14

nonmetallic covering

braid

6-2
1-4/0

1.52
2.03

60
80

Extended polytetra-

TFE

250^0

Dry locations only. Only

Extruded polytetra-

14-10

0.51

None

fluoro-

482T

for leads within

fluoroethylene

8-2

0.76

ethylene

apparatus or within
raceways connected to
apparatus, or as open
wiring (nickel or
nickel-coated copper
only)

1-4/0

1.14

Heat-resistant

THHN

90''C

Dry and damp locations

Flame-retardant,

14-12

0.38

Nylon jacket or

thermoplastic

194T ■

heat-resistant
thermoplastic

8-6

4-2

1^/0

250-500

501-1000

0.51
0.76
1.02
1.27
1.52
1.78

20
30
40
50
60
70

equivalent

Moisture- and

THHW

75°C

Wet location

Flame-retardant,

14-10

0.76

None

heat-resistant

167°F

moisture- and

' 8

1.14

thermoplastic

heat-resistant

6-2

1.52

90°C
194°F

Dry location

thermoplastic

1-4/0

213-500

501-1000

:1001>20p0

2.03
2.41
2.79
:3J8

110

:12A

Moisture- and

THW

75°C

Dry and wet locations

Flame-retardant,

14-10

0.76

None

heat-resistant

167°F

moisture- and

1.14

thermoplastic

90°C

Special applications

heat-resistant

6-2

1.52

194°F

within electric discharge
lighting equipment.
Limited to 1000
open-circuit volts or
less, (size 14-8 only as
permitted in 410.68)

thermoplastic

1^/0
213-500
501-1000
1001--200q

2.03
2.41
2.79
3.18

80
95
110

|125^

frHW-2

r90«C

pry' and wet Ipications

.194^F

Moisture- and

THWN

75''C

Dry and wet locations

Flame-retardant,

14-12

0.38

Nylon jacket or

heat-resistant

167°F

moisture- and

0.51

equivalent

thermoplastic

heat-resistant
thermoplastic

8-6
4-2

0.76
1.02

30
40

THWN-2

|90^C

1^/0
250-500
501-1000

1.27
1.52
1.78

50
60
70

Moisture-

60°C

Dry and wet locations

Flame-retardant,

14-10

0.76

None

resistant

140°F

moisture-

1.14

45 .

thermoplastic

resistant
thermoplastic

6-2

1-4/0
213-500
501-1000
1001-2000

1.52
2.03
2.41
2.79
3.18

60
80
95
110
125

Underground feeder

60°C

See Article 340.

Moisture-

14-10

1.52

601

Integral with insulation

and branch-circuit

140°F

resistant

8-2

2.03

8ol

cable — single

1^/0

2.41

^^i

conductor (for

Type UF cable

75°C

Moisture- and

employing more

167°F|

heat-resistant

than one

conductor, see

Article 340.)

70-142

2010 Califomia Electrical Code

ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING

310.13

Table 310.13|(A) ConHnued

Thickness of Insulation

Maximum Operating

TVade Name

Type Letter

Temperature

Application Provisions

Insulation

AWG or kcmil

mils

Outer Covering^

Underground

USE

75°C

See Article 338.

Heat- and

14-10

1.14

Moisture-resistant

service-

167'^F

moisture-resistant

8-2

1.52

nonmetallic covering

entrance cable —

1^/0

2.03

(See 338.2.)

single conductor

213-500

2.41

95i|

(for Type USE

501-1000

2.79

no'

cable employing

1001-2000

3.18

125

more than one

conductor, see

Article 338.)

}^Wl

rs?s

Dry;anJ' wibt" locations

J94*f*

Thermoset

XHH

90X

Dry and damp locations

Flame-retardant

14-10

0.76

None

194^F

thermoset

8-2

1-4/0

213-500

501-1000

1001-2000

1.14
1.40
1.65
2.03
2.41

45
55
65
80
95

Moisture-

XHHW^

90°C

Dry and damp locations

Flame-retardant,

14-10

0.76

None

resistant

194°F

moisture-

8-2

1.14

thermoset

75^C
167°F

Wet locations

resistant thermoset

1^/0
213-500
501-1000
1001-2000

1.40
1.65
2.03
2.41

55
65
80
95

Moisture-

XHHW-2

90"C

Dry and wet locations

Flame-retardant,

14-10

0.76

None

resistant

194°F

moisture-

8-2

1.14

thermoset

resistant thermoset

1-4/0
213-500
501-1000
1001-2000

1.40
1.65
2.03
2.41

55
65
80
95

Modified ethylene

90X

Dry and damp locations

Modified ethylene

14-12

0.38

None

tetrafluoro-

194°F

tetrafluoro-

0.51

ethylene

150°C

Dry locations — special

ethylene

8-4

0.64

302°F

applications^

3-1
1/0-4/0

0.89
1,14

35
45

Modified ethylene

1S°C

Wet locations

Modified ethylene

14-10

0.76

None

tetrafluoro-

\6TV

tetrafluoro-

8-2

1.14

ethylene

90°C
194T
150°C
302°F

Dry and damp locations

Dry locations — special
applications^

ethylene

zw-a

90"q

Dryland "Wet locations

■my

' Some insulations do not require an outer covering.

■^ Where design conditions require maximum conductor operating temperatures above 90°C (194°F).

^ For signaling circuits permitting 300-volt insulation.

•

^ Some rubber insulations do not require an outer covering.
^ Includes integral jacket.
^ For ampacity limitation, see 340.80.

^ Insulation thickness shall be permitted to be 2.03 mm (80 mils) for listed Type USE conductors that have
been subjected to special investigations. The nonmetallic covering over individual rubber-covered conduc-
tors of aluminum-sheathed cable and of lead-sheathed or multiconductor cable shall not be required to be
flame retardant. For Type MC cable, see 330.104. For nonmetallic- sheathed cable, see Article 334, Part III.
For Type UF cable, see Article 340, Part III.

2010 CaHfomia Electrical Code

70-143

310.13

ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING

Table 310.13(B) Thickness of Insulation for Nonshielded
Types RHH and BJBLW Solid DMectiicItisulated Conductors
Rated 2000 Volts

Column A^

Column B^

Conductor Size

(AWG or kcmil)

mils

14-10

2.03

1.52

2.03

1.78

6-2

2.41

1.78

1-2/0

2.79

110

2.29

90 ,

3/0-4/0

2.79

110

2.29

213-500

3.18

125

2.67

105

501-1000

3.56

140

3.05

120

1001-2000

3.56

140

3.56

140

tolumn A insulations are limited to natural, SBR, and butyl rubbers.

^Column B insulations are materials such as cross-linked
polyethylene, ethylene propylene rubber, and composites thereof.

Table 310.13(C| Conductor Application and Insulation Rated 2001 yolts and Higheij

Trade
Name

Type Letter

Maximum

Operating

Temperature

Application
Provision

Insulation

Outer Covering

Medium voltage
solid dielectric

MV-90
MV-105*

90°C
105°C

Dry or wet locations

•

Thermo-
plastic or thermo-
setting

Jacket, sheath, or
armor

* Where design conditions require maximum conductor temperatures above 90°C.

Table 310.13(D) Thickness of tnsulatibii^ and Jacket for Nonshielded Solid Dielectric Insiiil^ted; Cond^ Rated; 2400 Voll^

Dry Locations, Single Conductor

Wet or Dry Locations

Without Jacket
Insulation

With Jacket

Single Conductor

Multicondu(
Insulation

Insulation

Jacket

Insulation

Jacket

:tor

Conductor Size

(AWG or
kcmil)

mils

2.79

110

2.29

0.76

3.18

125

2.03

2.29

2.79

110

2.29

0.76

3.18

125

2.03

2.29

4-2

2.79

110

2.29

1.14

3.18

125

2.03

2.29

1-2/0

2.79

110

2.29

1.14

3.18

125

2.03

2.29

3/0-4/0

2.79

2.29

1.65

3.18

125

2.41

2.29

213-500

3.05

120

2.29

1.65

3.56

140

2.79

110

2.29

501-750

3.30

130

2.29

1.65

3.94

155

3.18

125

2.29

751-1000

3.30

130

2.29

1.65

3.94

155

3.18

125

2.29

mirnm

2,92

i0:

4:32

S70

3.56

U'^.

iisi-fism

%56

2,92

2.03

^<>

4.32

P9,

3.56

140

2S2

iSOMOpCi

346

l40

2,92

lis,

432

;17?

3.94

3^56

140

*Under a common overall covering such as a jacket, sheath, or armor.

70-144

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.15

Table 310.13(E) Thickness of Insulation for Shielded Solid Dielectric Insulated Conductors Rated 2001 to 35,000 Volts

2001-5000

Volts

5001-8000 Volts

8001-15,000 Volts

15,001-25,000 Volts

100

133

173

100 133

173

100 133

173

ftrctnt

Percent
Insulation

Percent Percent
Insulation Insulation

Percent
Insulation

Percent Percent
Insulation Insulation

Percent

Insulation

I-ev€l

Level 1

Level 2

Level3

Levell Level2

Level3

Levell Level2

Level3

Conductor

Size

(AWG

or kcmil) mm

mils

mm mils

mm mils mm

mils

mm mils

mm mils mm mils

mm mils

8 2.29

— —

_ _ . _

—

— —

_ _ _ _

_ __

6^ 2.29

2.92 115

3.56 140

4.45 175

— — —

—

— —

— — — —

— —

2 2 29

2 92 115

3 56 140

4 45 175

4.45 175 5.59
4.45 175 5.59

220
220

6 60 76ft

1 2.29

2.92 115

3.56 140

4.45 175

6.60 260

6.60 260 8.13 320

10.67 420

1/0-2000 2.29

2.92 115

3.56 140

4.45 175

4.45 175 5.59

220

6.60 260

6.60 260 8.13 320

10.67 420

25,001-

28,000 volts

28,001-35,000 volts

100

133

173

100

133

173

Percent

Insulation

Levell

Level 2

Level3

Levell

Level2

LeveB

Conductor

mm mils

mils

mm mils

Size

(AWG

or kcmil)

7.11 280

8.76

345

11. .30 445

— —

1/0-2000

7.11 280

8.76

345

11.30 445

8.76 345

10.67 420

14.73 580

100 Percent Insulation Level. Cables in this category shall be permitted to be applied where the system is provided with relay protection such that ground
faults will be cleared as rapidly as possible but, in any case, within 1 minute. While these cables are applicable to the great majority of cable installations that
are on grounded systems, they shall be permitted to be used also on other systems for which the application of cables is acceptable, provided the above
clearing requirements are met in completely de-energizing the faulted section.

^ 133 Percent Insulation Level. This insulation level corresponds to that formerly designated for ungrounded systems. Cables in this category shall be
permitted to be applied in situations where the clearing time requirements of the 100 percent level category cannot be met and yet there is adequate
assurance that the faulted section will be de-energized in a time not exceeding 1 hour. Also, they shall be permitted to be used in 100 percent insulation level
applications where additional insulation is desirable.
^ 173 Percent Insulation Level. Cables in this category shall be permitted to be apphed under all of the following conditions:

(1) In industrial establishments where the conditions of maintenance and supervision ensure that only qualified persons service the installation

(2) Where the fault clearing time requirements of the 133 percent level category cannot be met

(3) Where an orderly shutdown is essential to protect equipment and personnel

(4) There is adequate assurance that the faulted section will be de-energized in an orderly shutdown

Also, cables with this insulation thickness shall be permitted to be used in 100 or 133 percent insulation level applications where additional insulation
strength is desirable.

310.14 Aluminum Conductor Material. Solid aluminum
conductors 8, 10, and 12 AWG shall be made of an AA-
8000 series electrical grade aluminum alloy conductor
material. Stranded aluminum conductors 8 AWG through
1000 kcmil marked as Type RHH, RHW, XHHW, THW,
THHW, THWN, THHN, service-entrance Type SE Style U
and SE Style R shall be made of an AA-8000 series
electrical grade aluminum alloy conductor material.

310.15 Ampacities for Conductors Rated 0-2000 Volts.
(A) General.

(1) Tables or Engineering Supervision. Ampacities for
conductors shall be permitted to be determined by tables as
provided in 310.15(B) or under engineering supervision, as
provided in 310.15(C).

FPN No. 1 : Ampacities provided by this section do not take
voltage drop into consideration. See 210.19(A), FPN No. 4,
for branch circuits and 215.2(A), FPN No. 2, for feeders.
FPN No. 2: For the allowable ampacities of Type MTW
wire, see Table 13.5.1 in NFPA 79-2007, Electrical
Standard for Industrial Machinery.
(2) Selection of Ampacity. Where more than one
calculated or tabulated ampacity could apply for a given
circuit length, the lowest value shall be used.
Exception: Where two different ampacities apply to
adjacent portions of a circuit, the higher ampacity shall be
permitted to be used beyond the point of transition, a
distance equal to 3.0 m (10 ft) or 10 percent of the circuit
length figured at the higher ampacity, whichever is less.
FPN: See 110.14(C) for conductor temperature limitations
due to termination provisions.

2010 Califomia Electrical Code

70-145

310.15

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

(B) Tables. Ampacities for conductors rated to 2000
volts shall be as specified in the Allowable Ampacity Table
310.16 through Table 310.19, and Ampacity Table 310.20
and Table 3 10.21 as modified by (B)(1) through (B)(6).
FPN: Table 310.16 through Table 310.19 are application tables
for use in determining conductor sizes on loads calculated in
accordance with Article 220. Allowable ampacities result from
consideration of one or more of the following:

(1) Temperature compatibility with connected equipment,
especially the connection points.

(2) Coordination with circuit and system overcurrent
protection.

(3) Compliance with the requirements of product listings
or certifications. See 110.3(B).

(4) Preservation of the safety benefits of established
industry practices and standardized procedures.

(1) General. For explanation of type letters used in tables
and for recognized sizes of conductors for the various
conductor insulations, see Cfable' 3ip.l3(Al and Table
310.13^^ For installation requirements, see 310.1 through
310.10 and the various articles of this Code. For flexible
cords, see Table 400.4, Table 400.5(A), and Table
400.5(B).

(2) Adjustment Factors.

(a) More Than Three Current-Carrying Conductors in
a Raceway or Cable. Where the number of current-carrying
conductors in a raceway or cable exceeds three, or where
single conductors or multiconductor cables are iiisilBiled

than 600 mm (24 in.) and are not installed in raceways, the
allowable ampacity of each conductor shall be reduced as
shown in Table 310.15(B)(2)(a). Each current-carrying
conductor of a paralleled set of conductors shall be counted
as a current-carrying conductor.

Table 310.15(B)(2)(a) Adjustment Factors for More Than
Three Current-Carrying Conductors in a Raceway or Cable

Number of

Current-Carrying

Conductors

Percent of Values in Tables
310.16 through 310.19 as

Adjusted for Ambient
Temperature if Necessary

4-6

7-9

10-20

21-30

31^0

41 and above

80
70
50
45
40
35

FPN No. 2: See 366.23(A) for adjustment factors for
conductors in sheet metal auxiliary gutters and ^^^^H
for ^i^fr^i^ factors for conductors in metal wire ways.

Exception No. 1: Where conductors of different systems, as
provided in 300.3, are installed in a common raceway or
cable, the derating factors shown in Table 3 10 A 5(B)(2)(a)
shall apply only to the number of power and lighting
conductors (Articles 210, 215, 220, and 230).

Exception No. 2: For conductors installed in cable trays,
the provisions of 392.11 shall apply.

Exception No. 3: Derating factors shall not apply to
conductors in nipples having a length not exceeding 600
mm (24 in.).

Exception No. 4: Derating factors shall not apply to
underground conductors entering or leaving an outdoor
trench if those conductors have physical protection in the
form of rigid metal conduit, intermediate metal conduit, or
rigid nonmetallic conduit having a length not exceeding
3.05 m (10 ft) and if the number of conductors does not
exceedfour.

Exception No. 5: Adjustment factors shall not apply to
Type AC cable or to Type MC cable without an overall
outer jacket under the following conditions:

(1) Each cable has not more than three current-
carrying conductors.

(2) The conductors are 12 AWG copper.

(3) Not more than 20 current-carrying conductors are
bundled, stacked, or supported on "bridle rings. "

A 60 percent adjustment factor shall be applied where the
current-carrying conductors in these cables that are
stacked or bundled longer than 600 mm (24 in.) without
maintaining spacing exceeds 20.

(b) More Than One Conduit, Tube, or Raceway.
Spacing between conduits, tubing, or raceways shall be
maintained.

^ (c) 'Camhits Mx^osedJpSunl^^
^|i|ct^suailigM_ o^ afeoye rooftops, the adjuSietits showri

|5t^r||ure',for;;^^

FPN No. 1: See Annex B, Table B.310.11, for adjustment
factors for more than three current-carrying conductors in a
raceway or cable with load diversity.

'lo^tioxis.^^^

Fundumentaisl

; the; ASHRAE r Haadbook

70-146

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.15

Table 310.15(B)(2)(c) Ambient Temperature Adjustment for
Conduits Exposed to Sunligiit On or Above Rooftops

Distance Above Roof to
Bottom of Conduit

Temperature Adder

0-13 mm (1/2 in.) 33

Above 1 3 mm QA in.) - 90 22

mm (3/2 in.)

Above 90 mm (3^2 in.) - 17

300 mm (12 in.)

Above 300 mm (12 in.) - 14

900 mm (36 in.)

60
40

ioMt^^^MA^^^M ^^^^9}?^^^l.^Mi:M^J^^^ The

feeder conductors to a dv^elling unit shall not be required to
have an allov^able ampacity rating greater than their
service-entrance conductors. The grounded conductor shall
be permitted to be smaller than the ungrounded conductors,
provided the requirements of 215.2, 220.61, and 230.42
are met.

Table 310.15(B)(6) Conductor Types and Sizes for 120/240-
Volt, 3-Wire, Single-Phase Dv^^elling Services and Feeders.
Conductor Types RHH, RHW, RHW-2, THHN, THHW,
THW, THW-2, THWN, THWN-2, XHHW, XHHW-2, SE,
USE, USE-2

JRf N t^ t^ble 3i:0,i5(BX^Xft):;;T^^^ tetnp^atvire adde^^^

pPable '|lO, !'5(B)(2)(c) ,arr|kse§lon

(3) Bare or Covered Conductors. Where bare or covered
conductors are InstaUedj with insulated conductors, the;
jtetnperaty^e rating of the bare or covered conductor shall
be equal |o the lowest temperature ratiag of the ini^ulated
conductors for tte purpose of determining ampacity J

(4) Neutral Conductor.

(a) A neutral conductor that carries only the
unbalanced current fi-om other conductors of the same
circuit shall not be required to be counted when applying

the provisions of 3 1 0. 1 5(B)(2)(a).

(b) In a 3 -wire circuit consisting of two phase
conductor^ and the neutral jetodtictOT] of a 4- wire, 3 -phase,
wye-connected system, a common conductor carries
approximately the same current as the line-to-neutral load
currents of the other conductors and shall be counted when
applying the provisions of 310.15(B)(2)(a).

(c) On a 4-wire, 3 -phase v^e circuit where the major
portion of the load consists of nonlinear loads, harmonic
currents are present in the neutral conductor; the neutral
l^nductpj shall therefore be considered a current-carrying
conductor.

(5) Grounding or Bonding Conductor. A grounding or
bonding conductor shall not be counted when applying the
provisions of 310.15(B)(2)(a).

(6) 120/240-Volt, 3-Wire, Single-Phase Dwelling
Services and Feeders. For individual dwelling units of
one-family, two-family, and multifamily dwellings,
conductors, as listed in Table 310.15(B)(6), shall be
permitted as 120/240- volt, 3 -wire, single-phase service-
entrance conductors, service-lateral conductors, and feeder
conductors that serve as the main power feeder to each
dweUing unit and are installed in raceway or cable with or
without an equipment grounding conductor. For application
of this section, the main power feeder shall be the feeder
between the main disconnect and the panelboard 0iati
^ygppliies,^ither f y branch circm^ or by feederj^ qrjBpfc,^^^^

Conductor (AWG or kcmil)

Service or Feeder
Rating (Amperes)

Copper

Aluminum or

Copper-Clad

Aluminum

100
110
125
150
175
200
225
250
300
350
400

1/0
2/0
3/0
4/0
250
350
400

1/0
2/0
3/0
4/0
250
300
350
500
600

(C) Engineering Supervision. Under engineering
supervision, conductor ampacities shall be permitted to be
calculated by means of the following general formula:

/ =

TC-{TA^ATD)
RDC{14^¥C)RCA

where:

rC= conductor temperature in degrees Celsius (°C)
TA= ambient temperature in degrees Celsius C^C)

^TD= dielectric loss temperature rise

RDC= dc resistance of conductor at temperature TC

YC= component ac resistance resulting from skin
effect and proximity effect

RCA= effective thermal resistance between
conductor and surrounding ambient

FPN: See Annex B for examples of formula applications.

2010 California Electrical Code

70-147

310.15

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

Table 310.16 Allowable Ampacities of Insulated Conductors Rated Through 2000 Volts, 60°C Through 90°C (140°F Through
194°F), Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried), Based on Ambient
Temperature of 30°C (86°F)

Temperature Rating of Conductor [See Table 310J3(A),1

60°C (140°F)

75°C (167°F)

90°C (194°F)

60°C (140°F)

75°C (167°F)

90°C (194°F)

Types TBS, SA,

SIS, FEP, FEPB,

Types TBS, SA,

Types RHW,

MI, RHH, RHW-2,

Types RHW,

SIS, THHN,

THHW,

THHN, THHW,

THHW,

THHW, THW-2,

THW,

THW-2, THWN-2,

THW,

THWN-2, RHH,

THWN,

USE-2, XHH,

THWN,

RHW-2, USE-2,

Size

XHHW,

XHHW, XHHW-2,

Types TW,

XHHW,

XHH, XHHW,

AWGor

Types TW, UF

USE, ZW

ZW-2

USE

XHHW-2, ZW-2

Size AWG or

kcmil

COPPER

ALUMINUM OR COPPER-CLAD ALUMINUM

kcmil

18
16
14*

—

14
18

—

• 20

12*

10*

100

110

115

130

- 75

100

110

130

150

100

115

1/0

125

150

170

100

120

135

1/0

2/0

145

175

195

115

135

150

2/0

3/0

165

200

225

130

155

175

3/0

4/0

195

230

260

150

180

205

4/0

250

215

255

290

170

205

230

250

300

240

285

320

190

230

255

300

350

260

310

350

210

250

280

350

400

280

335

380

225

270

305

400

500

320

380

430

260

310

350

500

600

355

420

475

285

340

385

600

700

385

460

520

310

375

420

700

750

400

475

535

320

385

435

750

800

410

490

555

330

395

450

800

900

435

520

585

355

425

480

900

1000

455

545

615

375

445

500

1000

1250

495

590

665

405

485

545

1250

1500

520

625

705

435

520

585

1500

1750

545

650

735

455

545

615

1750

2000

560

665

750

470

560

630

2000

CORRECTION FACTORS

Ambient
Temp. (°C)

For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities shown above by the

appropriate factor shown below.

Ambient
Temp. (°F)

21-25

1.08

1.05

1.04

1.08

1.05

1.04

70-77

26-30

1.00

78-86

31-35

0.91

0.94

0.96

0.91

0.94

0.96

87-95

36-40

0.82

0.88

0.91

0.82

0.88

0.91

96-104

41^5

0.71

0.82

0.87

0.71

0.82

0.87

105-113

46-50

0.58

0.75

0.82

0.58

0.75

0.82

11^122

51-55

0.41

0.67

0.76

0.41

0.67

0.76

123-131

56-60

—

0.58

0.71

—

0.58

0.71

132-140

61-70

—

0.33

0.58

—

0.33

0.58

141-158

71-80

—

0.41

—

0.41

159-176

^ See 240.4(D).

70-148

2010 California Electrical Code

ARTICLE 31 - CONDUCTORS FOR GENERAL WIRING

310.15

Table 310.17 Allowable Ampacities of Single-Insulated Conductors Rated Through 2000 Volts in

Free Air, Based on

Ambient Air

Temperature of 30°C (86°F)

Temperature Rating of Conductor |si^!iiiiP9il(|il

60°C (140°F)

75^C (167^F)

90°C (194°F)

60°C (140°F)

75°C
(167°F)

90^C (194°F)

Types TBS, SA, SIS,

Types TBS, SA,

FEP, FEPB, MI,

Types

SIS, THHN,

Types RHW,

RHH, RHW-2,

RHW,

THHW, THW-2,

THHW,

THHN, THHW,

THHW,

THWN-2, RHH,

THW,

THW-2, THWN-2,

THW,

RHW-2, USE-2,

Size

THWN,

USE-2, XHH, XHHW,

thWn,

XHH, XHHW,

AWGor

Types TW, UF

XHHW, ZW

XHHW-2, ZW-2

Types TW, UF

XHHW

XHHW-2, ZW-2

Size AWG

kcmil

COPPER

ALUMINUM OR COPPER-CLAD ALUMINUM

or kcmil

—

14*

—

12*

10*

' 105

105

125

140

100

110

120

145

165

115

130

140

170

190

110

135

150

165

195

220

130

155

175

1/0

195

230

260

150

180

205

1/0

2/0

225

265

300

175

210

235

2/0

3/0

260

310

350

200

240

275

3/0

4/0

300

360

405

235

280

315

4/0

250

340

405

455

265

315

355

250

300

375

445

505

290

350

395

300

350

420

505

570

330

395

445

350

400

455

545

615

355

425

480

400

500

515

620

700

405

485

545

500

600

575

690

780

455

540

615

600

700

630

755

855

500

595

675

700

750

655

785

885

515

620

700

750

800

680

815

920

535

645

725

800

900

730

870

985

580

700

785

900

1000

780

935

1055

625

750

845

1000

1250

890

1065

1200

710

855

960

1250

1500

980

1175

1325

795

950

1075

1500

1750

1070

1280

1445

875

1050

1185

1750

2000

1155

1385

1560

960

1150

1335

2000

CORRECTION FACTORS

Ambient
Temp. (°C)

For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities shown above by the appropriate

factor shown below.

Ambient
Temp. (°F)

21-25

1.08

1.05

1.04

1.08

1.05

1.04

70-77

26-30

1.00

78-86

31-35

0.91

0.94

0.96

0.91

0.94

0.96

87-95

36^0

0.82

0.88

0.91

0.82

0.88

0.91

96-104

41-45

0.71

0.82

0.87

0.71

0.82

0.87

105-113

46-50

0.58

0.75

0.82

0.58

0.75

0.82

114-122

51-55

0.41

0.67

0.76

0.41

0.67

0.76

123-131

56-60

—

0.58

0.71

—

0.58

0.71

132-140

61-70

—

0.33

0.58

—

0.33

0.58

141-158

71-80

—

0.41

—

0.41

159-176

■ See 240.4(D).

2010 California Electrical Code

70-149

310.15

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

Table 310.18 Allowable Ampacities of Insulated Conductors Rated Through 2000 Volts, 150°C Through 250°C (302°r Through
482°F). Not More Than Three Current-Carrying Conductors in Raceway or Cable, Based on Ambient Air Temperature of 40°C
(104°F)

Temperature Rating of Conductor i$^§:Tm£ilSfX$M)S

150°C (302°F)

200°C (392°F)

250°C (482°F)

150°C (302°F)

Types FEP,

TypeZ

FEPB, PFA, SA

Types PFAH, TFE

TypeZ

NICKEL OR

ALUMINUM OR

NICKEL-COATED

COPPER-CLAD

COPPER

ALUMINUM

SizeAWGorkcmil

COPPER

Size AWG or kcmil

—

110

117

120

125

148

143

152

166

109

160

171

191

124

186

197

215

145

1/0

215

229

244

169

1/0

2/0

251

260

273

198

2/0

3/0

288

297

308

227

3/0

4/0

332

346

361

260

4/0

CORRECTION FACTORS

Ambient Temp.

(°C)

For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities
shown above by the appropriate factor shown below.

Ambient Temp. (°F)

41-50

0.95

0.97

0.98

0.95

105-122

51-60

0.90

0.94

0.95

0.90

123-140

61-70

0.85

0.90

0.93

0.85

141-158

71-80

0.80

0.87

0.90

0.80

159-176

81-90

0.74

0.83

0.87-

0.74

177-194

91-100

0.67

0.79

0.85

0.67

195-212

101-120

0.52

0.71

0.79

0.52

213-248

121-140

0.30

0.61

0.72

0.30

249-284

141-160

0.50

0.65

—

285-320

161-180

—

0.35

0.58

—

321-356

181-200

—

0.49

—

357-392

201-225

—

0.35

—

393^37

70-150

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.15

Table 310.19 Allowable Ampacities of Single-Insulated Conductors, Rated Through 2000 Volts, 150^C Through 250X (302°F
Through 482°F), in Free Air, Based on Ambient Air Temperature of 40°C (104^F)

Temperature Rating of Conductor 'iSti^^blkSMM&A

150°C

(302<^F)

200°C (392°F)

250°C(482°F)

150°C (302°F)

TypeZ

Types FEP,
FEPB, PFA, SA

Types PFAH,lFli:

TypeZ

SizeAWGorkcmil

COPPER

NICKEL, OR NICKEL-
COATED COPPER

ALUMINUM OR COPPER-
CLAD ALUMINUM

SizeAWGorkcmil

—

107

106

124

142

155

165

205

112

190

220

278

148

214

252

327

170

255

293

381

198

293

344

440

228

1/0

339

399

532

263

1/0

2/0

390

467

591

305

2/0

3/0

451

546

708

351

3/0

4/0

529

629*

830

411

4/0

CORRECTION FACTORS

Ambient Temp. (°Q

For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities shown
above by the appropriate factor shown below.

Ambient Temp. (°F)

41-50

0.95

0,97

0.98

0.95

105-122

51-60

0.90

0.94

0.95

0.90

123-140

61-70

0.85

0.90

0.93

0.85

141-158

71-80

0.80

0.87

0.90

0.80

159-176

81-90

0.74

0.83

0.87

0.74

177-194

91-100

0.67

0.79

0.85

0.67

195-212

101-120

0.52

0.71

0.79

0.52

213-248

121-140

0.30

0.61

0.72

0.30

249-284

141-160

—

0.50

0.65

—

285-320

161-180

—

0.35

0.58

—

321-356

181-200

—

0.49

—

357-392

201-225

— .

—

0.35

—

393^37

2010 California Electrical Code

70-151

310.15

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

Table 310.20 Ampacities of Not More Than Three Single Insulated Conductors, Rated Through 2000 Volts, Supported on a
Messenger, Based on Ambient Air Temperature of 40°C (104°F)

Temperature Rating of Conductor [See fable 3X0 JJC^^^

75°C (167°F)

90°C(194^F)

75°C (167°F)

90°C (194°F)

Types RHW,

THHW,THW,

THWN,XHHW,

Types MI, THHN,
THHW,THW-2,
THWN-2,RHH,
RHW-2,USE-2,
XHHW,XHHW-
2,ZW-2

Types RHW, THW,

IHWN,TIIHW,

XHHW

Types THHN, THHW,
RHH,XHHW,RHW-2,

XHHW-2,THW-2,
THWN-2,USE-2,ZW-2

SizeAWGorkcmil

COPPER

ALUMINUM OR COPPER-CLAD ALUMINUM

SizeAWGorkcmil

101

117

118

138

107

135

158

106

123

158

185

123

144

1/0

183

214

/143

167

1/0

2/0

212

247

165

193

2/0

3/0

245

287

192

224

3/0

4/0

287

335

224

262

4/0

250

320

374

251

292

250

300

359

419

282

328

300

350

397

464

312

364

350

400

430

503

339

395

400

500

496

580

392

458

500

600

553

647

440

514

600

700

610

714

488

570

700

750

638

747

512

598

750

800

660

773

532

622

800

900

704

826

572

669

900

1000

748

879

612

716

1000

CORRECTION FACTORS

Ambient Temp. (°C)

For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities shown
above by the appropriate factor shown below.

Ambient Temp. (°F)

21-25

1.20

1.14

1.20

1.14

70-77

26-30

1.13

1.10

1.13

1.10

79-86

31-35

1.07

1.05

1.07

1.05

88-95

36-40

1.00

97-104

41^5

0.93

0.95

0.93

0.95

106-113

46-50

0.85

0.89

0.85

0.89

115-122

51-55

0.76

0.84

0.76

0.84

124-131

' 56-60

0.65

0.77

0.65

0.77

133-140

61-70

0.38

0.63

0.38

0.63

142-158

71-80

—

0.45

— -

0.45

160-176

70-152

2010 California Electrical Code

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

310.15

Table 310.21 Ampacities of Bare or Covered Conductors in
Conductor Temperature, 610 mm/sec (2 ft/sec) Wind Velocity

Free Air, Based on 40^C (104°F) Ambient, 80°C (176°F) Total

Copper

Conductors

AAC Aluminum Conductors.

Bare

Covered

Bare

Covered

AWGor

AWG

AWGor

kcmil

Amperes

or kcmil

Amperes

kcmil

Amperes

kcmil

Amperes

103

124

130

101

155

163

121

127

209

219

163

171

1/0

282

1/0

297

1/0

220

1/0

231

2/0

329

2/0

344

2/0

255

2/0

268

3/0

382

3/0

401

3/0

297

3/0

312

4/0

444

4/0

466

4/0

346

4/0

364

250

494

250

519

266.8

403

266.8

423

300

556

300

584

336.4

468

336.4

492

500

773

500

812

397.5

522

397.5

548

750

1000

750

1050

477.0

588

477.0

617

1000

1193

1000

1253

556.5

650

556.5

682

—

636.0

709

636.0

744

—

795.0

819

795.0

860

—

954.0

920

—

1033.5

968

1033.5

1017

—

1272

1103

1272

1201

—

1590

1267

1590

1381

—

2000

1454

2000

1527

2010 California Electrical Code

70-153

310.60

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.60 Conductors Rated 2001 to 35,000 Volts.

(A) DeHnitions.

Electrical Ducts. As used in Article 310, electrical ducts
shall include any of the electrical conduits recognized in
Chapter 3 as suitable for use underground; other raceways
round in cross section, listed for underground use, and
embedded in earth or concrete.

Thermal Resistivity. As used in this Code, the heat transfer
capability through a substance by conduction. It is the
reciprocal of thermal conductivity and is designated Rho
and expressed in the units °C-cm/watt.

(B) Ampacities of Conductors Rated 2001 to 35,000
Volts. Ampacities for soHd dielectric-insulated conductors
shall be permitted to be determined by tables or under
engineering supervision, as provided in 310.60(C) and (D).

(1) Selection of Ampacity. Where more than one
calculated or tabulated ampacity could apply for a given
circuit length, the lowest value shall be used.

Exception: Where two different ampacities apply to
adjacent portions of a circuit, the higher ampacity shall be
permitted to be used beyond the point of transition, a
distance equal to 3,0 m (10 ft) or 10 percent of the circuit
length figured at the higher ampacity, whichever is less.

FPN: See 110.40 for conductor temperature Hmitations due
to termination provisions.

(C) Tables. Ampacities for conductors rated 2001 to
35,000 volts shall be as specified in the Ampacity Table
310.67 through Table 310.86. Ampacities at ambient
temperatures other than those shown in the tables shall be
determined by the formula in 3 10.60(C)(4).

FPN No. 1: For ampacities calculated in accordance with
310.60(B), reference IEEE 835-1994 (IPCEA Pub. No. P-
46-426), Standard Power Cable Ampacity Tables, and the
references therein for availability of all factors and
constants.

FPN No. 2: Ampacities provided by this section do not take
voltage drop into consideration. See 210.19(A), FPN No. 4,
for branch circuits and 215.2(A), FPN No. 2, for feeders.

(1) Grounded Shields. Ampacities shown in Table
310.69, Table 310.70, Table 310.81, and Table 310.82 are

for cable with shields grounded at one point only. Where
shields are grounded at more than one point, ampacities
shall be adjusted to take into consideration the heating due
to shield currents.

(2) Burial Depth of Underground Circuits. Where the
burial depth of direct burial or electrical duct bank circuits
is modified from the values shown in a figure or table,
ampacities shall be permitted to be modified as indicated in

(C)(2)(a) and (C)(2)(b).

(a) Where burial depths are increased in part(s) of an
electrical duct run, no decrease in ampacity of the
conductors is needed, provided the total length of parts of
the duct run increased in depth is less than 25 percent of the
total run length.

(b) Where burial depths are deeper than shown in a
specific underground ampacity table or figure, an ampacity
derating factor of 6 percent per 300-mm (1-ft) increase in
depth for all values of rho shall be permitted.

No rating change is needed where the burial depth is
decreased.

(3) Electrical Ducts in Figure 310.60. At locations where
electrical ducts enter equipment enclosures from under
ground, spacing between such ducts, as shown in Figure
310.60, shall be permitted to be reduced without requiring
the ampacity of conductors therein to be reduced.

(4) Ambients Not in Tables. Ampacities at ambient
temperatures other than those shown in the tables shall be
determined by means of the following formula:

h = iu

j TC-TA^-ATD
TC-TA-ATD

where:

/ 1= ampacity from tables at ambient TAi

1 2= ampacity at desired ambient TA2

TC= conductor temperature in degrees Celsius (°C)

TAi^ surrounding ambient from tables in degrees
Celsius (°C)

TA2= desired ambient in degrees Celsius (°C)
^TD= dielectric loss temperature rise

70-154

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.60

Detail 1

290 mm X 290 mm
{115 in, X 11 .5 In.)
Electrical duct bank
One electrical duct

190 mm {7.5 ia)

Detail 2

475 mm X 475 mm
(19 in. X 19 in.)
Eitctrical duct bank
Thme electrical ducts
or

190 mm 190 mm
(7,5 in,) (7.5 in J

675 mm x 290 mm
(27 in. X 115 in.)
Etectrical duct bank
Three etectrical ducts

Detail 5
Buried 3
oonductor
cable

600 mm

(24 in.)

Detail 6

Buried 3

conductor

cables

12^

T®®

05i^

' V ^ ,

^^2L

-®,®

g c

^ V

-® ® :

3. 'J

< ■ ■>^

190 mm (7.5 in.)

Details

475 mm X 675 mm
(19 in. X 27 in.)
Electrical duel bank
Six etectrical ducts
or

190 mm

(7.Bin.)

190 mm

(7.5 \n.)

675 mm X 475 mm
(27 in. X 19 in.)
Eiectrical duct bank
Six electrical ducts

190 mm
{IB in.)

190 mm
(7.5 m.)

Detail 7

Buried triplax^
cables (1 circuit)

190 mm 190 mm

(7.5 in.) (7,5 in,)

600 mm

(24 In.)

< H* H*"

# • *

600 mm

Details

Buried triplaxed
cables (2 circuils)

190 mm 190 mm
(7,5 in,) (7,5 in.)

(24 in.)

Detail 9

BuiwI slngle-conductor
cables (1 circuit)

Defaiil 10

Byri^ singla*conductor
cables (2 circyis)

Note: Minimum burial depths to top electrical ducts or cables shall be
in accordance with 300.50. Maximum depth to the top of electrical
duct banks shall be 750 mm (30 in.) and maximum depth to the top
of direct buried cables shall be 900 mm (36 in.).

Legend

f^ BackWI (earth or concrete)

O Electrical duct

• Cable or cabtes

Figure 310.60 Cable Installation Dimensions for Use with Table 310.77 Through Table 310.86.

2010 California Electrical Code

70-155

310.60

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

(D) Engineering Supervision. Under engineering
supervision, conductor ampacities shall be permitted to be
calculated by means of the following general formula:

Table 310.68 Ampacities of Insulated Single Aluminum
Conductor Cables Triplexed in Air Based on Conductor
Temperatures of 90°C (194°F) and 105^C (221°F) and
Ambient Air Temperature of 40°C(104°F)

j TC-{TA^ATD)

Tempei

-ature Rating of Conductor [S<

ee Table ^^lil?;©;.]

2001-

5000 Volts

5001-35,000 Volts

Conducto]

Ampacity

where:

r 90°C

105°C

90°C

105°C

TC=

conductor temperature in °

Size

(194°F) (221°F)

(194°F) 1

(22rF)

(AWG or

Type

lype

Type

TA=

ambient temperature in °C

kcmil)

MV-90 MV-105

MV.90 MV-105

AjY

)= dielectric loss temperature rise

RDC

'= dc resistance of conductor at temperature TC

100

110

YC= component ac resistance

effect anH nrnYimitv effect

resulting

from skin

2
1

125
145

135
160

130
150

150

175

■^

1/0

170

185

175

200

RCA

= effective

J thermal

resistance

between

2/0

195

215

200

230

conductor and surrounding ambient

3/0

225

250

230

265

FPN: Se

Q Annex B for examples of formula applications.

4/0

265

290

270

305

■ 250

295

325

300

335

350

365

405

370

415

Table 310.67 Ampacities of Insulated Single Copper

500

460

510

460

515

Conductor

Cables Triplexed in Air

Based on

Conductor

Temperatures of 90°C

(194°F) and

lOS^^C (22PF) and

750

600

665

590

660

Ambient Air Temperature of 40°C (104^F)

1000

715

800

700

780

Temperature

Rating of Conductor [See Table 310J3:((3,]

Table 310.69 Ampacities

of Insulated

Single

Copper

2001-5000 Volts

5001-35,000 Volts

Conductor Isolated

in Air Based on i

Conductor Temperatures

Ampacity

of 90°C
Temperati

(194°F) and 105°C (221°F) and Ambic
Lireof40°C(104°F)

snt Air

Conductor

90°C

105°C

90°C

105^C

Size

(194°F)

(221°F)

(194°F)

(221°F)

Temperature Rating of Conductor [S(

ee Table glfllCJ,)

(AWG

Type

2001-5000 Volts
Ampacity'

5001-15,000
Volts Ampacity

15,001-35,000
Volts Ampacity

or kcmil)

MV-90

MV-105

MV-90

MV-105

Conductor

90°C
(194°F)

105°C
(221°F)

90°C
(194°F)

105°C

(221°F)

90°C
(194°F)

105°C

(221°F)

Size

' —

—

(AWG

Type

Tjpe

Type

90
120

99
130

100
130

110
140

or kcmil)

MV-90

MV-105

MV-90

MV-105

MV-90

MV-105

—

110

120

110

125

—

160

175

170

195

145

160

150

165

—

185

205

195

225

2
1

190

225

215

250

195

225

215
250

225

—

1/0

215

240

225

255

250

1/0

260

290

260

290

260

290

2/0

250

275

260

295

2/0

300

330

300

335

300

330

3/0

290

320

300

340

3/0

345

385

345

385

345

380

4/0

335

375

345

390

4/0
250

400

445

445
495

400
445

445
495

395
440

445

250

375

415

380

430

490

350

550

615

550

610

545

605

350

465

515

470

525

500

695

lis

685

765

680

755

500

580

645

580

650

750

900

1000

885

990

870

970

750

835

730

820

1000

1075

1200

1060

1185

1040

1160

1000

880

980

850

950

1250
1500

1230
1365

1370
1525

1210
1345

1350
1500

1185
1315

1320
1465

1750

1495

1665

1470

1640

1430

1595

2000

1605

1790

1575

1755

1535

1710

70-156

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.60

Table 310.70 Ampacities of Insulated Single Aluminum
Conductor Isolated in Air Based on Conductor Temperatures
of 90°C (194^F) and 105°C (221°F) and Ambient Air
Temperature of 40°C (104°F)

Temperature Rating of Conductor [See Table 3i0.B (G),l

Conductor

Size

(AWG

or kcmil)

2001-5000 Volts
Ampacity

90°C 105X
(194°F) (22PF)

Type Type

MV-90 MV-105

5001-15,000
Volts Ampacity

90°C 105°C
(194°F) (221T)

Type Type
MV-90 MV-105

15,001-35,000
Volts Ampacity

90°C 105°C
(194<='F) (221°F)

Type Type
MV-90 MV-105

85
115
150
175

71
95
125
165
195

87
115
150
175

97
130
170
195

175

195

1/0

2/0
3/0
4/0

200 225

230 260

270 300

310 350

200
235
270
310

225
260
300
350

200
230
270
310

225
260
300
345

250
350
500
750

345 385

430 480

545 605

710 790

345
430
535
700

385
480
600
780

345
430
530
685

380
475
590
765

1000
1250
1500
1750
2000

855 950

980 1095

1105 1230

1215 1355

1320 1475

840
970
1085
1195
1295

940
1080
1215
1335
1445

825
950
1060
1165
1265

920
1055
1180
1300
1410

Table 310.71 Ampacities of an Insulated Three-Conductor
Copper Cable Isolated in Air Based on Conductor
Temperatures of 90°C (194°F) and 105°C (22PF) and
Ambient Air Temperature of 40^C (104^F)

Temperature Rating
310^

of Conductor [See Table

Conductor

Size

(AWG

or kcmil)

2001-5000 Volts
Ampacity

90°C 105°C

(194°F) (221°F)

Type Type

MV-90 MV-105

5001-35,000 Volts
Ampacity

90^C
(194°F)

Type
MV-90

105°C
(221°F)

Type
MV-105

59
79
105
140
160

88
115
154
180

93
120
165
185

105
135
185
210

1/0
2/0
3/0
4/0

185
215
250
285

205
240
280
320

215
245
285
325

240
275
315
360

250
350
500
750
1000

320
395
485
615
705

355
440
545
685
790

360
435
535
670
770

400
490
600

745
860

Table 310.72 Ampacities of an Insulated Three-Conductor
Aluminum Cable Isolated in Air Based on Conductor
Temperatures of 90^C (194°F) and 105°C (221°F) and
Ambient Air Temperature of 40°C (104°F)

Temperature Rating of Conductor [See Table $WM (Qt,]

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor

Size

(AWG

or kcmil)

90^C
(194°F)

Type
MV-90

105°C

(221°F)

Type
MV-105

90°C
(194^F)

Type
MV-90

105°C

(22PF)

Type

MV-105

46
61

110

125

51
68
90
120
140

72
95
125
145

80
105
145
165

1/0

145

160

170

185

2/0

170

185

190

215

3/0

195

215

220

245

4/0

225

250

255

285

250
350
500
750
1000

250
310
385
495
585

280
345
430
550
650

280
345
425
540
635

315
385
475
600
705

Table 310.73 Ampacities of an Insulated Triplexed or Three
Single-Conductor Copper Cables in Isolated Conduit in Air
Based on Conductor Temperatures of 90°C (194°F) and
105°C (221'^F) and Ambient Air Temperature of 40°C (104°F)

Temperature Rating of Conductor [See Table 3l0;i3 <Q,]

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor

Size

(AWG

or kcmil)

90°C
(194°F)

Type
MV-90

105X

(22FF)

Type
MV-105

90°C
(194°F)

Type
MV-90

105°C
(221°F)

Type
MV-105

55
75
97
130
155

110

145

175

83
110
150
170

93
120
165
190

1/0

2/0
3/0
4/0

180
205
240
280

200
225
270
305

195

225
260
295

215
255
290
330

250
350
500
750
1000

315
385
475
600
690

355
430
530
665
770

330
395
480
585
675

365
440
535
655
755

2010 California Electrical Code

70-157

310.60

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

Table 310.74 Ampacities of an Insulated Triplex ed or Three
Single-Conductor Aluminum Cables in Isolated Conduit in
Air Based on Conductor Temperatures of 90°C (194°F) and
lOS^C (22PF) and Ambient Air Temperature of 40°C (104°F)

Table 310.76 Ampacities of an Insulated Three-Conductor
Aluminum Cable in Isolated Conduit in Air Based on
Conductor Temperatures of 90°C (194°F) and 105°C (221°F)
and Ambient Air Temperature of 40°C (104°F)

Temperature Rating of Conductor [See Table 1^10,13 (Cj,l

Temperaturt

; Rating of Conductor [See Tabl

leaiO,B(C|,l

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor

Size

(AWG

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

90°C
(194°F)

Type
MV-90

105°C
(221°F)

Type
MV-105

90°C
(194°F)

Type
MV-90

105°C
(221'^F)

Type
MV-105

Conductor

Size

(AWG

or kcmil)

90°C
(194°F)

Type

105°C
(221°F)

Type

90°C
(194°F)

Type

105°C

(22FF)

Type

43
58

48
65

or kcmil)

MV-90

MV-105

MV-90

MV-105

—

2
1

76
100
120

85
115
135

84
115
130

94
130
150

4
2

53
71
96

59
79
105

64
84
115

1/0

140

155

150

170

125

2/0

160

190

175
210

175
200

200

225

110

125

130

145

3/0

1/0

130

145

150

170

4/0

215

240

230

260

2/0
3/0

150

170

165 ■
190

170
195

190

250

280

255

290

220

350
500
750

305
380
490

340
425
545

310

385
485

350

430
540

4/0

200

225

255

250

220

245

250

280

1000

580

645

565

640

350
500

275
340

305
380

340

Table 310.75 Ampacities of an Insulated Three-Conductor

425

Copper Cable in Isolated Conduit
Temperatures of 90°C (194*^F)
Ambient Air Temperature of 40°C

in Air Based on
and 105°C (2

(i04°r)

jnductor [SeeTabh

Conductor
21°F) and

750
1000

430
505

480
560

470
550

520
615

Temperature Rating of C<

;mi3(qi,]

2001-5000 Volts

5001-35,000 Volts

Ampacity

Conductor

90°C

105°C

90°C

105°C

Size

(194<^F)

(221°F)

(194°F)

(22PF)

(AWG

Type

or kcmil)

MV-90

MV-105

MV-90

MV-105

—

100

105

120

125

135

145

165

140

155

165

185

1/0

165

185

195

215

2/0

190

210

220

245

3/0

220

245

250

280

4/0

255

285

290

320

250

280

315

350

390

385

430

500

425

475

470

525

750

525

585

570

635

1000

590

660

650

725

70-158

2010 California Electrical Code

ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING

310.60

Table 310.77 Ampacities of Three Single-Insulated Copper
Conductors in Underground Electrical Ducts (Three
Conductors per Electrical Duct) Based on Ambient Earth
Temperature of 20^C (68°F), Electrical Duct Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures of 90°C
(194°F) and 105°C (22PF)

Table 310.78 Ampacities of Three Single-Insulated
Aluminum Conductors in Underground Electrical Ducts
(Three Conductors per Electrical Duct) Based on Ambient
Earth Temperature of 20°C (68°F), Electrical Duct
Arrangement per Figure 310.60, 100 Percent Load Factor,
Thermal Resistance (RHO) of 90, Conductor Temperatures of
90^C (194^F) and lOS^C (221°F)

Temperature Rating of Conductor

[See Table 3id.i3l:€),l

Temperatui

re Rating of Conductor [See Table 3l€i3 (Q,]

2001-5000 Volts

5001-35,000 Volts

2001-!

5000 Volts

5001-35,000 Volts

Ampacity

Conductor

Ampacity

Conductor

90°C

105°C

90'^C

105°C

90°C

105°C

90°C

105°C

Size

(194°F)

(221°F)

(194°F)

(221°F)

Size

(194°F)

(221°F)

(194°F)

(221°F)

(AWG

Type

(AWG

Type

or kcmil)

MV-90

MV-105

MV-90

MV-105

or kcmil)

MV-90

MV-105

MV-90

MV-105

One Circuit

(See Figure

310.60, Detail 1.)

OneCu-cuit(

;See Figure 310.60, Detail 1.)

—

110

120

115

125

145

155

165

115

125

120

130

170

180

175

185

130

140

135

145

1/0

195

210

200

215

2/0

220

235

230

245

3/0

250

270

260

275

4/0

290

310

295

315

1/0

150

160

155

165

2/0

170

185

175

190

3/0

195

210

200

215

4/0

225

245

230

245

250
350
500
750
1000

320
385
470
585
670

345
415
505
630
720

Three Circuits (See Figure 310.60, Detail 2.)

56
73
95
125
140

60
79
100
130
150

325

345

390

415

465

500

565

610

640

690

—

105

130

135

145

155

250
350
500
750
1000

250
305
370
470
545

270
325
400
505
590

Three Cu-cuits (See Figure 310.60, DetaH 2.)

44
57
74
96
110

47
61
80
105
120

1/0

160

175

165

175

2/0

185

195

185

200

3/0

210

225

210

225

4/0

235

255

240

255

250
350
500
750
1000

260

315
375
460
525

280
335
405
495
565

Six Circuits (See Figure 310.60, Detail 3.)

48
62
80
105
115

52
67
86
110
125

260

280

310

330

370

395

440

475

495

535

105

115

120

125

250
350
500
750
1000

205
245
295
370
425

220
265
320
395
460

Six Circuits (See Figure 310.60, Detail 3.)

38
48
62
80
91

41
52
67
86
98

1/0

135

145

135

145

2/0

150

160

150

165

3/0

170

185

170

185

4/0

195

210

190

205

250

270

305

330

370

400

455

490

525

565

—

100

105

110

120

1/0

125

135

125

140

2/0

145

155

145

155

3/0

160

175

165

175

4/0

185

200

185

200

220

245

260

290

315

355

385

405

440

1/0

105

110

105

110

2/0

115

125

115

125

3/0

135

145

130

145

4/0

150

165

150

160

250

210

225

210

225

250

165

180

165

175

350

250

270

245

265

350

195

210

195

210

500

300

325

290

310

500

240

255

230

250

750

365

395

350

375

750

290

315

280

305

1000

410

445

390

415

1000

335

360

320

345

2010 California Electrical Code

70-159

310.60

ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING

Table 310.79 Ampacities of Three Insulated Copper
Conductors Cabled Within an Overall Covering (Three-
Conductor Cable) in Underground Electrical Ducts (One
Cable per Electrical Duct) Based on Ambient Earth
Temperature of 20°C (68°F), Electrical Duct Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures of 90°C
(194°F) and lOS'^C (221°C)

Temperature Rating of Conductor [See Table 310.13 (€),J

Conductor

Size

(AWG

or kcmil)

2001-5000 Volts
Ampacity

90°C

(194°F)

Type MV-

105°C

(221°F)

Type MV-

105

5001-35,000 Volts
Ampacity

90°C
(194°F)

Type
MV-90

One Circuit (See Figure 310.60, Detail 1.)

59
78
100
135
155

64
84
110
145
165

115
150
170

250
350
500
750
1000

290
355
430
530
600

315
380
460
570
645

310
375
450
545
615

53
69
89
115
135

57
74
96
125
145

75
97
125
140

250
350
500
750
1000

245
295
355
430
485

265
315

380
465
520

255
305
360
430
485

Six Circuits (See Figure 310.60, Detail 3.)

46
60
77
98
110

50
65
83
105
120

63
81
105
115

105°C
(221°F)

Type
MV-105

95
125
160
185

1/0

175

190

195

210

2/0

200

220

235

3/0

230

250

270

4/0

265

285

305

335
400
485
585
660

Three Circuits (See Figure 310.60, Detail 2.)

81
105
135
155

1/0

150

165

160

175

2/0

170

185

195

3/0

195

210

205

220

4/0

225

240

230

250

270
325
385
465
515

68
87
110
125

1/0

125

135

130

145

2/0

145

155

150

160

3/0

165

175

170

180

4/0 .

185

200

190

200

Table 310.80 Ampacities of Three Insulated Aluminum
Conductors Cabled Within an Overall Covering (Three-
Conductor Cable) in Underground Electrical Ducts (One
Cable per Electrical Duct) Based on Ambient Earth
Temperature of 20°C (68°r), Electrical Duct Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures of 90°C
(194°F) and 105°C (221°C)

Temperature Rating of Conductor [See Table 31043 (Q,]

2001-5000 Volts

Ampacity

Conductor 90°C 105°C
Size (194°F) (221°F)
(AWG Type MV- Type MV-
or kcmil) 90 105

5001-35,000 Volts
Ampacity

90°C
(194°F)

Type
MV-90

One Circuit (See Figure 310.60, Detail 1.)

46
61
80
105
120

50
66
86
110
130

69
89
115
135

250
350
500
750
1000

230
280
340
425
495

245
310
365
460
535

245
295
355
440
510

41
54
70
90
105

44
58
75
97
110

59
75
100
110

250
350
500
750
1000

190
230
280
345
400

205
250
300
375
430

200
240
285
350
400

Six Circuits (See Figure 310.60, Detail 3.)

36
46
60

77
87

39
50
65
83
94

49
63
80
90

105°C

(221°F)

Type
MV-105

74
96
125
145

1/0

140

150

165

2/0

160

170

185

3/0

180

195

210

4/0

205

220

240

265
315
385
475
545

Three Circuits (See Figure 310.60, Detail 2.)

64
81
105
120

1/0

120

125

135

2/0

135

145

140

155

3/0

155

165

160

175

4/0

175

185

180

195

215
255
305
375
430

86
98

1/0

105

110

2/0

110

120

115

125

3/0

130

140.

130

140

4/0

145

155

150

160

250

200

220

205

220

250

160

170

160

170

350

240

270

245

275

350

190

205

190

205

500

290

310

290

305

500

230

245

230

245

750

350

375

340

365

750

280

305

275

295

1000

390

420

380

405

1000

320

345

315

335

70-160

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.60

Table 310.81 Ampacities of Single Insulated Copper
Conductors Directly Buried in Earth Based on Ambient Earth
Temperature of 20°C (68°F), Arrangement per Figure 310.60,
100 Percent Load Factor, Thermal Resistance (RHO) of 90,
Conductor Temperatures of 90°C (194°F) and 105°C (221°C)

Table 310.82 Ampacities of Single Insulated Aluminum
Conductors Directly Buried in Earth Based on Ambient Earth
Temperature of 20^C (68°F), Arrangement per Figure 310.60,
100 Percent Load Factor, Thermal Resistance (RHO) of 90,
Conductor Temperatures of 90°C (194°F) and 105°C (221°F)

Temperature

! Rating of Conductor [See Table 31045 (€),]

Temperature Rating of Conductor [See Table

3WJ!3i(E),]

2001-5000 Volts

5001-35,000 Volts

2001-5000 Volts

5001-35,000 Volts

Ampacity

Conductor

Ampacity

Conductor

90°C

105°C

90^C

105°C

90°C

105°C

90°C

105°C

Size

(194°F)

(221°F)

(194'^F)

(221°F)

Size

(194°F)

(221°F)

(194°F)

(221°F)

(AWG

Type

(AWG

Type

or kcmil)

MV-90

MV-105

MV-90

MV-105

or kcmil)

MV-90

MV-105

MV-90

MV-105

One Circuit, Three Conductors (See Figure 310.60,

Detail 9.)

One Circuit, Three Conductors (See Figure

310.60, DetaU 9.)

110

115

—

140

150

130

140

110

115

100

110

180

195

170

180

140

150

130

140

230

250

210

225

180

195

165

175

260

280

240

260

205

220

185

200

1/0

295

320

275

295

1/0

230

250

215

230

2/0

335

365

310

335

2/0

265

285

245

260

3/0

385

415

355

380

3/0

300

320

275

295

4/0

435

465

405

435

4/0

340

365

315

340

250

470

510

440

475

250

370

395

345

370

350

570

615

535

575-

350

445

480

415

450

500

690

745

650

700

500

540

580

510

545

750

845

910

805

865

750

665

720

635

680

1000

980

1055

930

1005

1000

780

840

740

795

Two Circui

its. Six Conductors (See

100 110

Figure 310.60, Detail 10.)

Two Circuits, Six Conductors (See Figure 310.60, Detail 10.)

8 .

—

130

140

120

130

100

110

100

165

180

160

170

130

140

125

130

215

230

195

210

165

180

155

165

240

260

225

240

190

200

175

190

1/0

275

295

255

275

1/0

215

230

200

215

2/0

310

335

290

315

2/0

245

260

225

245

3/0

355

380

330

355

3/0

275

295

255

275

4/0

400

430

375

405

4/0

310

335

290

315

250

435

470

410

440

250

340

365

320

345

350

520

560

495

530

350

410

440

385

415

500

630

680

600

645

500

495

530

470

505

750

775

835

740

795

750

610

655

580

625

1000

890

960

855

920

1000

710

765

680

730

2010 California Electrical Code

70-161

310.60

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

Table 310.83 Ampacities of Three Insulated Copper
Conductors Cabled Within an Overall Covering (Three-
Conductor Cable), Directly Buried in Earth Based on
Ambient Earth Temperature of 20°C (68°F), Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures of 90*'C
(194°F) and 105°C (22PF)

Table 310.84 Ampacities of Three Insulated Aluminum
Conductors Cabled Within an Overall Covering (Three-
Conductor Cable), Directly Buried in Earth Based on
Ambient Earth Temperature of 20°C (68°F), Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures of 90°C
(194°F) and 105^C (22PF)

Temperature

! Rating of Conductor [See Table miS(C),j

Temperature Rating of Conductor [See Tabl

le3JM?jgSl

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor
Size

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor
Size

90^C
(194°F)

105°C
(221°F)

90°C
(194°F)

105^C
(221°F)

90°C
(194°F)

105°C
(221°F)

90°C
(194°F)

105°C

(22rF)

(AWG
or kcmil)

Type
MV-90

Type
MV-105

Type
MV-90

Type
MV-105

(AWG

or kcmil)

Type
MV-90

Type
MV-105

Type
MV-90

Type
MV-105

One Circuit

(See Figure 310.60, Detail 5.)

One Circuit (See Figure 310.60, DetaU 5.)

—

105

115

120

135

150

145

155

105

115

125

180

190

185

200

140

150

145

155

200

215

210

225

155

170

165

175

1/0

230

245

240

255

1/0

180

190

185

200

2/0

260

280

270

290

2/0

205

220

210

225

3/0

295

320

305

330

3/0

230

250

240

260

4/0

335

360

350

375

4/0

260

280

270

295

250

365

395

380

410

250

285

310

300

320

350

440

475

460

495

350

345

375

360

390

500

530

570

550

590

500

420

450

435

470

750

650

700

665

720

750

520

560

540

580

1000

730

785

750

810

1000

600

650

620

665

Two Circuits (See Figure 310.60, DetaO 6.)

Two Qrcuits (See Figure 310.60, DetaU 6.)

—

100

105

115

130

140

135

145

100

110

105

115

165

180

170

185

130

140

135

145

185

200

195

210

145

155

150

165

1/0

215

230

220

235

1/0

165

180

170

185

2/0

240

260

250

270

2/0

190

205

195

210

3/0

275

295

280

305

3/0

215

230

220

240

4/0 ■

310

335

320

345

4/0

245

260

250

270

250

340

365

350

375

250

265

285

275

295

350

410

440

420

450

350

320

345

330

355

500

490

525

500

535

500

385

415

395

425

750

595

640

605

650

750

480

515

485

525

1000

665

715

675

730

1000

550

590

560

600

70-162

2010 California Electrical Code

ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING

310.60

Table 310.85 Ampacities of Three Triplexed Single Insulated
Copper Conductors Directly Buried in Earth Based on
Ambient Earth Temperature of 20°C (68^F), Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures 90°C
(194^r) and 105°C (221°F)

Table 310.86 Ampacities of Three Triplexed Single Insulated
Aluminum Conductors Directly Buried in Earth Based on
Ambient Earth Temperature of 20°C (68°F), Arrangement
per Figure 310.60, 100 Percent Load Factor, Thermal
Resistance (RHO) of 90, Conductor Temperatures 90°C
(194°F) and 105°C (221°F)

Temperature Rating of Conductor [See Table 310.13 j[C),]

Temperature

Rating of Conductor [See Table aiftBffiM

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor
Size

2001-5000 Volts
Ampacity

5001-35,000 Volts
Ampacity

Conductor
Size

90°C (194°F)

105°C

(221°F)

90°C
(194°F)

105°C

(221°F)

90°C
(194°F)

105°C

(22PF)

90°C
(194°F)

105^C
(221°F)

(AWG
or kcmil)

Type
MV-90

Type
MV-105

Type
MV-90

Type
MV-105

(AWG
or kcmil)

Type
MV-90

Type
MV-105

Type
MV-90

Type
MV-105

One Circuit

, Three Conductors (See Figure

90 95

j310.60,DetaO7.)

One Circuit, Three Conductors (See Figure 310.60, DetaU 7.)

—

120

130

115

120

100

150

165

150

160

120

130

115

125

195

205

190

205

155

165

145

155

225

240

215

230

175

190

165

175

1/0

255

270

245

260

1/0

200

210

190

205

2/0

. 290

310

275

295

2/0

225

240

215

230

3/0

330

360

315

340

3/0

255

275

245

265

4/0

375

405

360

385

4/0

290

310

280

305

250

410

445

390

410

250

320

350

305

325

350

490

580

470

505

350

385

420

370

400

500

590

635

565

605

500

465

500

445

480

750

725

780

685

740

750

580

625

550

590

1000

825

885

770

830

1000

670

725

635

680

Two Circuits, Six Conductors (See Figure 310.60, DetaU 8.)

Two Circuits, Sbc Conductors (See Figure

i 310.60, Detail 8.)

—

110

115

105

115

140

150

140

150

110

120

105

115

180

195

175

190

140

150

135

145

205

220

200

215

160

170

155

170

1/0

235

250

225

240

1/0

180

195

175

190

2/0

265

285

255

275

2/0

205

220

200

215

3/0

300

320

290

315

3/0

235

250

225

245

4/0

340

365

325

350

4/0

265

285

255

275

250

370

395

355

380

250

290

310

280

300

350

445

480

425

455

350

375

335

360

500

535

575

510

545

500

420

455

405

435

750

650

700

615

660

750

520

560

485

. 525

1000

740

795

690

745

1000

600

645

565

605

2010 California Electrical Code

70-163

312.1

ARTICLE 3 12 - CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES

ARtICLE3l2

Cabinets, Cutout Boxes, and Meter Socket
;'':' 'Enclosures^'O V:,\ '

312.1 Scope. This article covers the installation and
construction specifications of cabinets, cutout boxes, and
meter socket enclosures.

I. Installation

312.2 DaiByp^:.a|Ld,"W0^ . In damp or wet

locations, surface-type enclosures within the scope of this
article shall be placed or equipped so as to prevent moisture
or water from entering and accumulating within the cabinet
or cutout box, and shall be mounted so there is at least 6-
mm (y4-in.) airspace between the enclosure and the wall or
other supporting surface. Enclosures installed in wet
locations shall be weatherproof For enclosures in wet
locations, raceways or cables entering above the level of
uninsulated live parts shall use fittings listed for wet
locations.

Exception: Nonmetallic enclosures shall be permitted to be
installed without the airspace on a concrete, masonry, tile,
or similar surface.

FPN: For protection against corrosion, see 300.6.

312.3 Position in Wall. In walls of concrete, tile, or other
noncombustible material, cabinets shall be installed so that
the front edge of the cabinet is not set back of the finished
surface more than 6 mm (% in.). In walls constructed of
wood or other combustible material, cabinets shall be flush
with the finished surface or project therefrom.

312^_ Repairing ^fesfflisS^

SoBCombii^tfblgj surfaces that are broken or incomplete
shall be repaired so there will be no gaps or open spaces
greater than 3 mm (1/8 in.) at the edge of the cabinet or
cutout box employing a flush-type cover.

312.5 Cabinets, Cutout Boxes, and Meter Socket
Enclosures. Conductors entering enclosures within the
scope of this article shall be protected from abrasion and
shall comply with 312.5(A) through (C).

(A) Openings to Be Closed. Openings through which
conductors enter shall be adequately closed.

(B) Metal Cabinets, Cutout Boxes, and Meter Socket
Enclosures. Where metal enclosures within the scope of this
article are installed with messenger-supported wiring, open
wiring on insulators, or concealed knob-and-tube wiring,
conductors shall enter through insulating bushings or, in dry
locations, through flexible tubing extending from the last
insulating support and firmly secured to the enclosure.

Exception: Cables with entirely nonmetallic sheaths shall
be permitted to enter the top of a surface-mounted
enclosure through one or more nonflexible raceways not
less than 450 mm (18 in.) and not more than 3.0 m (10 ft)
in length, provided all of the following conditions are met:

(a) Each cable is fastened within 300 mm (12 in.),
measured along the sheath, of the outer end of the raceway.

(b) The raceway extends directly above the enclosure
and does not penetrate a structural ceiling.

(c) A fitting is provided on each end of the raceway to
protect the cable (s) from abrasion and the fittings remain
accessible after installation.

(d) The raceway is sealed or plugged at the outer end
using approved means so as to prevent access to the
enclosure through the raceway.

(e) The cable sheath is continuous through the
raceway and extends into the enclosure beyond the fitting
not less than 6 mm (Vi in.).

(f) The raceway is fastened at its outer end and at
other points in accordance with the applicable article.

(g) Where installed as conduit or tubing, the allowable
cable fill does not exceed that permitted for complete
conduit or tubing systems by Table 1 of Chapter 9 of this
Code and all applicable notes thereto.

FPN: See Table 1 in Chapter 9, including Note 9, for
allowable cable fill in circular raceways. See
310.15(B)(2)(a) for required ampacity reductions for
multiple cables installed in a common raceway.

312.6 Deflection of Conductors. Conductors at terminals
or conductors entering or leaving cabinets or cutout boxes
and the like shall comply with 312.6(A) through (C).

Exception: Wire-bending space in enclosures for motor
controllers with provisions for one or two wires per
terminal shall comply with 430. 1 0(B),

(A) Width of Wiring Gutters. Conductors shall not be
deflected within a cabinet or cutout box unless a gutter
having a width in accordance with Table 312.6(A) is
provided. Conductors in parallel in accordance with 310.4
shall be judged on the basis of the number of conductors in
parallel.

(B) Wire-Bending Space at Terminals. Wire-bending
space at each terminal shall be provided in accordance with
312.6(B)(1) or (B)(2).

(1) Conductors Not Entering or Leaving Opposite
Wall. Table 312.6(A) shall apply where the conductor does
not enter or leave the enclosure through the wall opposite
its terminal.

70-164

2010 California Electrical Code

ARTICLE 3 12 - CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES

312.10

Table 312.6(A) Minimum Wire-Bending Space at Terminals and Minimum Width of Wiring Gutters

Wires per Terminal

Wire Size

(AWG or kcmil)

in.

14-10

Not;

specified

—

8-6

38,1

V/i

—

4-3

50.8

—

63.5

2/2

—

76.2

—

1/0-2/0

88.9

3^/2

127

178

—

3/0-4/0

102

152

203

—

250

114

4/2

152

203

254

—

300-350

127

203

254

305

—

400-500

152

203

254

305

356

600-700

203

254

305

356

406

750-900

203

305

356

406

457

1000-1250

254

—

1500-2000

305

—

Note: Bending space at terminals shall be measured in a straight line fi*om the end of the lug or wire connector (in the direction that the
wire leaves the terminal) to the wall, barrier, or obstruction.

(2) Conductors Entering or Leaving Opposite Wall.

Table 312.6(B) shall apply where the conductor does enter
or leave the enclosure through the wall opposite its
terminal.

Exception No, 1: Where the distance between the wall and
its terminal is in accordance with Table 312.6(A), a
conductor shall be permitted to enter or leave an enclosure
through the wall opposite its terminal, provided the
conductor enters or leaves the enclosure where the gutter
joins an adjacent gutter that has a width that conforms to
Table 312. 6(B) for the conductor.

Exception No. 2: A conductor not larger than 350 kcmil
shall be permitted to enter or leave an enclosure
containing only a meter socket (s) through the wall opposite
its terminal provided the distance between the terminal
and the opposite wall is not less than that specified in
Table 312.6(A) and the terminal is a lay-in type, where the
terminal is either of the following:

(a) Directed toward the opening in the enclosure and
within a 45 degree angle of directly facing the enclosure
wall

(b) Directly facing the enclosure wall and offset not
greater than 50 percent of the bending space specified in
Table 312.6(A)

FPN: Offset is the distance measured along the enclosure
wall from the axis of the centerline of the terminal to a line
passing through the center of the opening in the enclosure.

312.7 Space in Enclosures. Cabinets and cutout boxes
shall have sufficient space to accommodate all conductors
installed in them without crowding.

312.8 Enclosures for Switches or Overcurrent Devices.

Enclosures for switches or overcurrent devices shall not be
used as junction boxes, auxiliary gutters, or raceways for
conductors feeding through or tapping off to other switches
or overcurrent devices, unless adequate space for this
purpose is provided. The conductors shall not fill the
wiring space at any cross section to more than 40 percent
of the cross-sectional area of the space, and the conductors,
splices, and taps shall not fill the wiring space at any cross
section to more than 75 percent of the cross-sectional area
of that space.

312.9 Side or Back Wiring Spaces or Gutters. Cabinets
and cutout boxes shall be provided with back-wiring
spaces, gutters, or wiring compartments as required by
312.11(C) and (D).

II. Construction Specifications

312.10 Material. Cabinets, cutout boxes, and meter socket
enclosures shall comply with 312.10(A) through (C).

(A) Metal Cabinets and Cutout Boxes. Metal enclosures
within the scope of this article shall be protected both
inside and outside against corrosion.

FPN: For information on protection against corrosion, see
300.6.

(B) Strength. The design and construction of enclosures
within the scope of this article shall be such as to secure
ample strength and rigidity. If constructed of sheet steel,
the metal thickness shall not be less than 1.35 mm (0.053
in.) uncoated.

2010 California Electrical Code

70-165

312.10

ARTICLE 312 - CABINETS, CUTOUT BOXES, AND METER SOKET ENCLOSURES

Table 312.6(B) Minimum Wire-Bending Space at Terminals

Wires per Terminal

Wire Size (AWG or kcmil)

4 or

Compact
Stranded AA-

8000 Aluminum

All Other
Conductors

Alloy
Conductors
(See Note 3.)

mm in.

in.

14-10

12-8

Not specified

—

38.1 V/2

—

50.8 2

—

76.2 3

—

76.2 3

—

1/0

88.9 3/2

—

2/0

114 4^2

—

___

1/0

3/0

. 140 5/2

140

5/2

178

—

2/0

4/0

152 6

152

190

7^2

—

3/0

250

165^ 6^2^

165^

6/2^

203

—

4/0

300

jygb 7b

190^

7/2^

216^

8'/2^

—

250

350

216^ 8/2^

229^

8^/2^

254^

254

300

400

254^ 10^

254^

10^

279^

lib

305

350

500

. 305^ . 12^

305^

12^

330^

13^

356^

14d

400

600

330^ 13^

330^

13^

356^

14e

381^

15^

500

700-750

356^ 14^

356^

14e

381^

15^

406^

16^

600

800-900

381^ 15^

406^

16^

457^

18^

483^

19^

700

1000

406^ 16^

457^

18^

508^

20^

559^

22e

750

432^ 17^

483^

19e

559^

22e

610^

24e

800

—

457 18

508

559

610

900

—

483 19

559

610

1000

—

508 . 20

—

1250

—

559 22

—

1500

—

610 24

—

1750

—

610 24

—

2000*

—

610 24

—

1. Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in a direction perpendicular to
the enclosure wall.

2. For removable and lay-in wire terminals intended for only one wire, bending space shall be permitted to be reduced by the following
number of millimeters (inches):

^ 12.7 mm (Yi in.) ^ 50.8 mm (2 in.)

b 25.4 mm (1 in.) ^ 76.2 mm (3 in.)

^38.1mm(U/2in.)

3. This column shall be permitted to determine the required wire-bending space for compact stranded aluminum conductors in sizes up to
1000 kcmil and manufactured using AA-8000 series electrical grade aluminum alloy conductor material in accordance with 310.14.

70-166

2010 Cahfomia Electrical Code

ARTICLE 314 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES

314.3

(C) Nonmetallic Cabinets. Nonmetallic cabinets shall be
listed, or they shall be submitted for approval prior to
installation.

312.11 Spacing. The spacing within cabinets and cutout
boxes shall comply with 312.1 1(A) through (D).

(A) General. Spacing within cabinets and cutout boxes
shall be sufficient to provide ample room for the
distribution of wires and cables placed in them and for a
separation between metal parts of devices and apparatus
mounted within them in accordance with (A)(1), (A)(2),
and (A)(3).

(1) Base. Other than at points of support, there shall be an
airspace of at least 1.59 mm (0.0625 in.) between the base
of the device and the wall of any metal cabinet or cutout
box in which the device is mounted.

(2) Doors. There shall be an airspace of at least 25.4 mm
(1.00 in.) between any live metal part, including live metal
parts of enclosed fuses, and the door.

Exception: Where the door is lined with an approved
insulating material or is of a thickness of metal not less
than 2.36 mm (0.093 in.) uncoated, the airspace shall not
be less than 12. 7 mm (0.500 in.).

(3) Live Parts. There shall be an airspace of at least 12.7
mm (0.500 in.) between the walls, back, gutter partition, if
of metal, or door of any cabinet or cutout box and the
nearest exposed current-carrying part of devices mounted
within the cabinet where the voltage does not exceed 250.
This spacing shall be increased to at least 25.4 mm (1.00
in.) for voltages of 251 to 600, nominal.

Exception: Where the conditions in 312.11(A)(2), Exception,
are met, the airspace for nominal voltages from 251 to 600
shall be permitted to be not less than 12. 7 mm (0.500 in.).

(B) Switch Clearance. Cabinets and cutout boxes shall be
deep enough to allow the closing of the doors when 30-
ampere branch-circuit panelboard switches are in any
position, when combination cutout switches are in any
position, or when other single-throw switches are opened
as far as their construction permits.

(C) Wiring Space. Cabinets and cutout boxes that contain
devices or apparatus connected within the cabinet or box to
more than eight conductors, including those of branch
circuits, meter loops, feeder circuits, power circuits, and
similar circuits, but not including the supply circuit or a
continuation thereof, shall have back-wiring spaces or one
or more side-wiring spaces, side gutters, or wiring
compartments.

(D) Wiring Space — Enclosure. Side-wiring spaces, side
gutters, or side-wiring compartments of cabinets and cutout

boxes shall be made tight enclosures by means of covers,
barriers, or partitions extending from the bases of the
devices contained in the cabinet, to the door, frame, or
sides of the cabinet.

Exception: Side-wiring spaces, side gutters, and side-
wiring compartments of cabinets shall not be required to
be made tight enclosures where those side spaces contain
only conductors that enter the cabinet directly opposite to
the devices where they terminate.

Partially enclosed back-wiring spaces shall be
provided with covers to complete the enclosure. Wiring
spaces that are required by 312.11(C) and are exposed
when doors are open shall be provided with covers to
complete the enclosure. Where adequate space is provided
for feed-through conductors and for splices as required in
312.8, additional barriers shall not be required.

Outlet J Device, Pull^ and Junction Boxes;
Conduit Bodies; Fittings J and Handtiole
^' ■ Enclosures . ' = ■ /' ''.^-\. . .

I. Scope and General

314.1 Scope. This article covers the installation and use of
all boxes and conduit bodies used as outlet, device,
junction, or pull boxes, depending on their use, and
handhole enclosures. Cast, sheet metal, nonmetallic, and
other boxes such as FS, FD, and larger boxes are not
classified as conduit bodies. This article also includes
installation requirements for fittings used to join raceways
and to connect raceways and cables to boxes and conduit
bodies.

314.2 Round Boxes. Round boxes shall not be used where
conduits or connectors requiring the use of locknuts or
bushings are to be connected to the side of the box.

314.3 Nonmetallic Boxes. Nonmetallic boxes shall be
permitted only with open wiring on insulators, concealed
knob-and-tube wiring, cabled wiring methods with entirely
nonmetallic sheaths, flexible cords, and nonmetallic
raceways.

Exception No. 1: Where internal bonding means are
provided between all entries, nonmetallic boxes shall be
permitted to be used with metal raceways or metal-
armored cables.

Exception No. 2: Where integral bonding means with a
provision for attaching an equipment bonding jumper

2010 California Electrical Code

70-167

314.4

ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES

inside the box are provided between all threaded entries in

nonmetallic boxes listed for the purpose, nonmetallic boxes

shall be permitted to be used with metal raceways or

metal-armored cables.

314 A Metal Boxes. Metal bo^^^^

FoMed in accordka^ witli Pafe^^ of

i^&ii^ffli^ ^ """^ "" " "'

314.5 Short-Radius Conduit Bodies. Conduit bodies
such as capped elbows and service -entrance elbows that
enclose conductors 6 AWG or smaller, and are only
intended to enable the installation of the raceway and the
contained conductors, shall not contain splices, taps, or
devices and shall be of sufficient size to provide free space
for all conductors enclosed in the conduit body.

II. Installation

314.15 Damp or Wet Locations. In damp or wet
locations, boxes, conduit bodies, and fittings shall be
placed or equipped so as to prevent moisture from entering
or accumulating within the box, conduit body, or fitting.
Boxes, conduit bodies, and fittings installed in wet
locations shall be listed for use in wet locations.

FPN No. 1 : For boxes in floors, see 3 14.27(C).
FPN No. 2: For protection against corrosion, see 300.6.
#

314.16 Number of Conductors in Outlet, Device, and
Junction Boxes, and Conduit Bodies. Boxes and conduit
bodies shall be of sufficient size to provide free space for
all enclosed conductors. In no case shall the volume of the
box, as calculated in 314.16(A), be less than the fill
calculation as calculated in 314.16(B). The minimum
volume for conduit bodies shall be as calculated in
314.16(C).

The provisions of this section shall not apply to terminal
housings supplied with motors &tgfetfgmti|l.

FPN: For volume requirements of motor jfrigenerit^

terminal housings, see 430.12.

Boxes and conduit bodies enclosing conductors 4 AWG or
larger shall also comply with the provisions of 314.28.
(A) Box Volume Calculations. The volume of a wiring
enclosure (box) shall be the total volume of the assembled
sections and, where used, the space provided by plaster
rings, domed covers, extension rings, and so forth, that are
marked with their volume or are made from boxes the
dimensions of which are listed in Table 314.16(A).
(1) Standard Boxes. The volumes of standard boxes that
are not marked with their volume shall be as given in Table
314.16(A).

(2) Other Boxes. Boxes 1650 cm3 (100 in.3) or less, other
than those described in Table 314.16(A), and nomnetallic
boxes shall be durably and legibly marked by the
manufacturer with their volume. Boxes described in Table
314.16(A) that have a volume larger than is designated in
the table shall be permitted to have their volume marked as
required by this section.

(B) Box Fill Calculations. The volumes in paragraphs
314.16(B)(1) through (B)(5), as applicable, shall be added
together. No allowance shall be required for small fittings
such as locknuts and bushings.

(1) Conductor Fill. Each conductor that originates outside
the box and terminates or is spliced within the box shall be
counted once, and each conductor that passes through the
box without splice or termination shall be counted once.
!l§?bJpJ9PJM.?S?L<i^u^b conductor not less than twice
the minimum length required for free conductors in 300.14
shall be counted twice. The conductor fill shall be
calculated using Table 314.16(B). A conductor, no part of
which leaves the box, shall not be counted.

Exception: An equipment grounding conductor or
conductors or not over four fixture wires smaller than 14
AWG, or both, shall be permitted to be omitted from the
calculations where they enter a box from a domed
luminaire or similar canopy and terminate within that box.

(2) Clamp Fill. Where one or more internal cable clamps,
whether factory or field supplied, are present in the box, a
single volume allowance in accordance with Table
314.16(B) shall be made based on the largest conductor
present in the box. No allowance shall be required for a
cable connector with its clamping mechanism outside the
box.

(3) Support Fittings Fill. Where one or more luminaire
studs or hickeys are present in the box, a single volume
allowance in accordance with Table 314.16(B) shall be
made for each type of fitting based on the largest conductor
present in the box.

(4) Device or Equipment Fill. For each yoke or strap
containing one or more devices or equipment, a double
volume allowance in accordance with Table 314.16(B)
shall be made for each yoke or strap based on the largest
conductor connected to a device(s) or equipment supported
by that yoke or strap. ^Jdgvice^^u^

III' Tay^ ^^^WM.^^^- 'h^f^PHMZ^!^!.!^^ . ^^^9:pi
gmviHed for^each/gang lequjr^/or mi^^

(5) Equipment Grounding Conductor Fill. Where one
or more equipment grounding conductors or equipment
bonding jumpers enter a box, a single volume allowance
in accordance with Table 314.16(B) shall be made based
on the largest equipment grounding conductor or equip -

70-168

2010 California Electrical Code

ARTICLE 314 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES 314.17

Table 314.16(A)

Metal Boxes

Box Trade Size

Minimum Volume

Maximum Number of Conductors*
i(krratt^d 'by ^A^wS^isiz^

in.

3
cm

3
in.

100 X 32

(4x11/4)

round/octagonal

205

12.5

100 X 38

(4x 11/2)

round/octagonal

254

15.5

100 X 54

(4 X 2%)

round/octagonal

353

21.5

100 X 32

(4x 1%)

square

295

18.0

100 X 38

(4x 1V4)

square

344

21.0

100 X 54

(4 X 2%)

square

497

30.3

120 X 32

(4"A6xP/4)

square

418

25.5

120x38

(4^Vi6xiy2)

square

484

29.5

120 X 54

(4' V|6 X 2%)

square

689

42.0

75 X 50 x 38

(3x2x11/2)

device

123

7.5

75 X 50 X 50

(3x2x2)

device

164

10.0

75 X 50 X 57

(3 X 2 X 2/4)

device

172

10.5

75X50X.65

(3 X 2 X 2/2)

device

205

12.5

75 X 50 X 70

(3 X 2 X 2y4)

device

230

14.0

75 X 50 X 90

(3 X 2 X 3/2)

device

295

18.0

100 X 54 X 38

(4x2^8x1/2)

device

169

10.3

100 X 54 X 48

(4 X 2y8x V/s)

device

213

13.0

100 X 54 X 54

(4 X 2/8 X 2/8)

device

238

14.5

95 X 50 X 65

(3/4 X 2 X 2/2)

masonry box/gang

230

14.0

95 X 50 X 90

(374 X 2 X 3/2)

masonry box/gang

344

21.0

min. 44.5 depth

FS — single cover/gang (VA)

221

13.5

min. 60.3 depth

FD — single cover/gang (IVs)

295

18.0

min. 44.5 depth

FS — multiple cover/gang (1/4)

295

18.0

min. 60.3 depth

FD — multiple cover/gang (278)

395

24.0

* Where no voume allowances are required by 314.16(B)(2) through (B)(5).

Table 314.16(B) Volume Allowance Required per Conductor

Free Space Within Box for Each
Conductor

Size of Conductor
(AWG)

cm^

in.3

24.6

1.50

28.7

1.75

32.8

2.00

36.9

2.25

41.0

2.50

49.2

3.00

81.9

5.00

merit bonding jumper present in the box. Where an
additional set of equipment grounding conductors, as
permitted by 250.146(D), is present in the box, an additional
volume allowance shall be made based on the largest
equipment grounding conductor in the additional set.

(1) General. Conduit bodies enclosing 6 AWG conductors
or smaller, other than short-radius conduit bodies as
described in 314.5, shall have a cross-sectional area not
less than twice the cross-sectio^nal area of the largest
conduit or tubing to which fey can bd attached. The
maximum number of conductors permitted shall be the
maximum number permitted by Table 1 of Chapter 9 for
the conduit or tubing to which it is attached.

(2) With Splices, Taps, or Devices. Only those conduit
bodies that are durably and legibly marked by the
manufacturer with their volume shall be permitted to
contain splices, taps, or devices. The maximum number of
conductors shall be calculated in accordance with
314.16(B). Conduit bodies shall be supported in a rigid and
secure manner.

314,17 Conductors Entering Boxes, Conduit Bodies, or
Fittings. Conductors entering boxes, conduit bodies, or

2010 California Electrical Code

70-169

314.19

ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES

fittings shall be protected from abrasion and shall comply
with 314.17(A) through (D).

(A) Openings to Be Closed. Openings through which
conductors enter shall be adequately closed.

(B) Metal Boxes and Conduit Bodies. Where metal boxes
or conduit bodies are installed with messenger-supported
wiring, open wiring on insulators, or concealed knob-and-
tube wiring, conductors shall enter through insulating
bushings or, in dry locations, through flexible tubing
extending fi-om the last insulating support to not less than 6
mm (% in.) inside the box and beyond any cable clamps.
Except as provided in 300.15(C), the wiring shall be firmly
secured to the box or conduit body. Where raceway or
cable is installed with metal boxes or conduit bodies, the
raceway or cable shall be secured to such boxes and
conduit bodies.

(C) Nonmetallic Boxes and Conduit Bodies. Nonmetallic
boxes and conduit bodies shall be suitable for the lowest
temperature-rated conductor entering the box. Where
nonmetallic boxes and conduit bodies are used with
messenger-supported wiring, open wiring on insulators, or
concealed knob-and-tube wiring, the conductors shall enter the
box through individual holes. Where flexible tubing is used to
enclose the conductors, the tubing shall extend from the last
insulating support to not less than 6 mm (Va in.) inside the box
and beyond any cable clamp. Where nonmetallic-sheathed
cable or multiconductor Type UF cable is used, the sheath
shall extend not less than 6 mm (% in.) inside the box and
beyond any cable clamp. In all instances, all permitted wu-ing
methods shall be secured to the boxes.

Exception: Where nonmetallic-sheathed cable or

multiconductor Type UF cable is used with single gang
boxes not larger than a nominal size 57 mm ^100 mm (2V4
in. X 4 in.) mounted in walls or ceilings, and where the cable
is fastened within 200 mm (8 in.) of the box measured along
the sheath and where the sheath extends through a cable
knockout not less than 6 mm (V4 in.), securing the cable to
the box shall not be required. Multiple cable entries shall be
permitted in a single cable knockout opening.

(D) Conductors 4 AWG or Larger. Installation shall
comply with 300.4(G).

FPN: See 110.12(A) for requirements on closing unused
cable and raceway knockout openings.

314.19 Boxes Enclosing Flush Devices. Boxes used to
enclose flush devices shall be of such design that the
devices will be completely enclosed on back and sides and
substantial support for the devices will be provided. Screws
for supporting the box shall not be used in attachment of
the device contained therein.

314.20 In Wall or Ceiling. In walls or ceilings with a surface
of concrete, tile, gypsum, plaster, or other noncombustible
material, boxes employing a flush-type cover or faceplate shall
be installed so that the front edge of the box, plaster ring,

extension ring, or listed extender will not be set back of the
finished surface more than 6 mm QA in.).

In walls and ceilings constructed of wood or other
combustible surface material, boxes, plaster rings,
extension rings, or listed extenders shall be flush with the
finished surface or project therefrom.

314.21 Repairing Plaster and Drywall or Plasterboard.

Plaster, drywall, or plasterboard surfaces that are broken or
incomplete around boxes employing a flush-type cover or
faceplate shall be repaired so there will be no gaps or open
spaces greater than 3 mm (1/8 in.) at the edge of the box.

314.22 Surface Extensions. Surface extensions shall be
made by mounting and mechanically securing an extension
ring over the box. Equipment grounding shall be in
accordance with t*art VI of Article 250.

Exception: A surface extension shall be permitted to be
made from the cover of a box where the cover is designed
so it is unlikely to fall off or be removed if its securing
means becomes loose. The wiring method shall be flexible
for a length sufficient to permit removal of the cover and
provide access to the box interior, and arranged so that
any grounding continuity is independent of the connection
between the box and cover.

314.23 Supports. Enclosures within the scope of this
article shall be supported in accordance with one or more
of the provisions in 314.23(A) through (H).

(A) Surface Mounting. An enclosure mounted on a
building or other surface shall be rigidly and securely
fastened in place. If the surface does not provide rigid and
secure support, additional support in accordance with other
provisions of this section shall be provided.

(B) Structural Mounting. An enclosure supported from a
structural member of a building or from grade shall be
rigidly supported either directly or by using a metal,
polymeric, or wood brace.

(1) Nails and Screws. Nails and screws, where used as a
fastening means, shall be attached by using brackets on the
outside of the enclosure, or they shall pass through the
interior within 6 mm (% in.) of the back or ends of the
enclosure. Screws shall not be permitted to pass through
the box unless exposed threads in the box are protected
using approved means to avoid abrasion of conductor
insulation.

(2) Braces. Metal braces shall be protected against
corrosion and formed from metal that is not less than 0.51
mm (0.020 in.) thick uncoated. Wood braces shall have a
cross section not less than nominal 25 mm x 50 mm (1 in.
X 2 in.). Wood braces in wet locations shall be treated for

70-170

2010 California Electrical Code

ARTICLE 3 14 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES

314.23

the conditions. Polymeric braces shall be identified as
being suitable for the use.

(C) Mounting in Finisiied Surfaces. An enclosure
mounted in a finished surface shall be rigidly secured
thereto by clamps, anchors, or fittings identified for the
application.

(D) Suspended Ceilings. An enclosure mounted to
structural or supporting elements of a suspended ceiling
shall be not more than 1650 cm3 (100 in. 3) in size and
shall be securely fastened in place in accordance with
either (D)(1) or (D)(2).

(1) Framing Members. An enclosure shall be fastened to
the framing members by mechanical means such as bolts,
screws, or rivets, or by the use of clips or other securing
means identified for use with the type of ceiling framing
member(s) and enclosure(s) employed. The framing
members shall be adequately supported and securely
fastened to each other and to the building structure.

(2) Support Wires. The installation shall comply with the
provisions of 300.11(A), The enclosure shall be secured, using
methods identified for the purpose, to ceiling support wire(s),
including any additional support wire(s) installed for that
purpose. Support wire(s) used for enclosure support shall be
fastened at each end so as to be taut within the ceiling cavity.

(E) Raceway Supported Enclosure, Without Devices,
Luminaires, or Lampholders. An enclosure that does not
contain a device(s) other than splicing devices or support a
luminaire(s), lampholder, or other equipment and is
supported by entering raceways shall not exceed 1650 cm3
(100 in. 3) in size. It shall have threaded entries or have
hubs identified for the purpose. It shall be supported by two
or more conduits threaded wrenchtight into the enclosure or
hubs. Each conduit shall be secured within 900 mm (3 ft)
of the enclosure, or within 450 mm (18 in.) of the enclosure
if all conduit entries are on the same side.

Exception: Rigid metal, intermediate metal, or rigid
nonmetallic conduit or electrical metallic tubing shall he
permitted to support a conduit body of any size, including a
conduit body constructed with only one conduit entry,
provided the trade size of the conduit body is not larger
than the largest trade size of the conduit or electrical
metallic tubing.

(F) Raceway-Supported Enclosures, with Devices,
Luminaires, or Lampholders. An enclosure that contains
a device(s), other than splicing devices, or supports a
luminaire(s), lampholder, or other equipment and is
supported by entering raceways shall not exceed 1650 cm3
(100 in.3) in size. It shall have threaded entries or have
hubs identified for the purpose. It shall be supported by two

or more conduits threaded wrenchtight into the enclosure or
hubs. Each conduit shall be secured within 450 mm (18 in.)
of the enclosure.

Exception No. 1: Rigid metal or intermediate metal
conduit shall be permitted to support a conduit body of any
size, including a conduit body constructed with only one
conduit entry, provided the trade size of the conduit body is
not larger than the largest trade size of the conduit.

Exception No. 2: An unbroken length(s) of rigid or
intermediate metal conduit shall be permitted to support a
box used for luminaire or lampholder support, or to
support a wiring enclosure that is an integral part of a
luminaire and used in lieu of a box in accordance with
300.15(B), where all of the following conditions are met:

(a) The conduit is securely fastened at a point so that
the length of conduit beyond the last point of conduit
support does not exceed 900 mm (3 ft).

(b) The unbroken conduit length before the last point
of conduit support is 300 mm (12 in.) or greater, and that
portion of the conduit is securely fastened at some point
not less than 300 mm (12 in) from its last point of support.

(c) Where accessible to unqualified persons, the
luminaire or lampholder, measured to its lowest point, is at
least 2,5 m (8 ft) above grade or standing area and at least
900 mm (3 ft) measured horizontally to the 2.5 m (8 ft)
elevation from windows, doors, porches, fire escapes, or
similar locations.

(d) A luminaire supported by a single conduit does not
exceed 300 mm (12 in.) in any direction from the point of
conduit entry.

(e) The weight supported by any single conduit does
not exceed 9 kg (20 lb).

(f) At the luminaire or lampholder end, the conduit(s)
is threaded wrenchtight into the box, conduit body, or
integral wiring enclosure, or into hubs identified for the
purpose. Where a box or conduit body is used for support,
the luminaire shall be secured directly to the box or
conduit body, or through a threaded conduit nipple not
over 75 mm (3 in.) long.

(G) Enclosures in Concrete or Masonry. An enclosure
supported by embedment shall be identified as suitably
protected from corrosion and securely embedded in
concrete or masonry.

(H) Pendant Boxes. An enclosure supported by a pendant
shall comply with 314.23(H)(1) or (H)(2).

(1) Flexible Cord. A box shall be supported from a
multiconductor cord or cable in an approved manner that
protects the conductors against strain, such as a strain-relief
connector threaded into a box with a hub.

(2) Conduit. A box supporting lampholders or luminaires,
or wiring enclosures within luminaires used in lieu of

2010 California Electrical Code

70-171

Iii§i

ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES

boxes in accordance with 300.15(B), shall be supported by
rigid or intermediate metal conduit stems. For stems longer
than 450 mm (18 in.), the stems shall be connected to the
wiring system with flexible fittings suitable for the
location. At the luminaire end, the conduit(s) shall be
threaded wrenchtight into the box or wiring enclosure, or
into hubs identified for the purpose.

Where supported by only a single conduit, the threaded
joints shall be prevented from loosening by the use of set-
screws or other effective means, or the luminaire, at any
point, shall be at least 2.5 m (8 ft) above grade or standing
area and at least 900 mm (3 ft) measured horizontally to the
2.5 m (8 ft) elevation from windows, doors, porches, fire
escapes, or similar locations. A luminaire supported by a
single conduit shall not exceed 300 mm (12 in.) in any
horizontal direction from the point of conduit entry.
314.24 Minimfim Depth of Bote% for Outlets. DevicesJ

have sufficient depth to allow ^qnij^mmt msiaUed withiil
f hem to be mounted p^roperly and with mfficimt clearance
jto ptevetit damagejoxotiduotoi^ withm the boK.
JtAlT Outlet BQ^es Without Enclosed EN g^ices or ytiliza%ii!

iqgig^ig^^t JNoJ^ ^ internal depth of less tfaari

(B) lOiitiet and Deyii^e Box^ with Enclosed Bevices. Bqxe^

iiifendod to enclosejusfi devices shaff^^ m inteinal depth of

notless AaB 218 |OT^^ in',),

(Q^'Uttpzation\Equ^^ QMS^i^^M deyJ.?^ boxes that

bgd^se Mliza^c§^ jxitm^

jdep Jhi , &at . accoxhm^jattes ihe rearwardi^^^ oi ihi

6qmpmQiit and the sias of th& condv^is^^^at sijppiy the
equipmen^^ Mtoal depth shall inc&dfej ^ere use4 tii^tpf
any extension boxes, piaster rings, or raised mycm. Tlie mtemal
dq>tii shall comply with all appHcabie provisions of (C)(l]

SllM; ___,„.,„ ,^^I1„_ . [1

.{13^'Large EqvipjXLmt^^^ .^jg^^e^^jitilization

i^u^ent ftiatpt^jg^^

ftooji the mounting plane of teboxstetf hav^ a dgpthtfaat is koj
less thm the depth of the eqmpment plus 6 mm QA in,)

pX„ Conductors^ I^pger TIiot 4 AWG, "Boxes that eiKJiosei

jajfeafipn ^ equipmeni^^sjppW fp^-A

p)_^^ Gottductor$ J^^^ ^utii^SttQ

egm^eS gjppUeJ^^ 'sMlSvi^

mtemal, deplii tet is nbt te^^ti^ 52Aiimi^)M M;)l
(4)jCoiidiictors 12 or JO AW& Boxes tot ^clo^ ttflmtipn
^egmpment,stfflHea,bxl2 or id A^G conducfe shall^^ve at^
Intemai dq^ iiat is not less tfel 30 J fa^ Where S^

§^rneM;^^^ pf _fli|

Ifoi by moie than ZB mm (J Hn.), the:bjdx;shMl '^ a deptti

hot less than^tto of th^el '^quij)ment plnS;6^tnm^(^^^

^(^^^ ; Cbiidwetpi? 14 AWG aiid^Sitta^ Boxes Jm^encfpse

jeguipnGient supplied by 14 AWG or staalier conductes shall

have ajtepth&at B;npt les| ft^23.8ton|y^^^^

Exception to (Q^l)thtm^ (C)(5): Utitization equiprmnl
'that is Uit0d ip b^ imt0 boxes shalTbi^

permitted!

314.25 Covers and Canopies. In completed installations,
each box shall have a cover, faceplate, lampholder, or
luminaire canopy, except where the installation complies
with 410.24(B).

(A) Nonmetallic or Metal Covers and Plates. Nonmetalhc or
metal covers and plates shall be permitted. Where metal covers
or plates are used, they shall comply with the grounding
requirements of 250.1 10.

FPN: For additional grounding requirements, see 410.42(A)
for metal luminaire canopies, and 404.12 and 406.5(B) for
metal faceplates.

(B) Exposed Combustible Wall or Ceiling Finish. Where
a luminaire canopy or pan is used, any combustible wall or
ceiling finish exposed between the edge of the canopy or
pan and the outlet box shall be covered with
noncombustible material.

(C) Flexible Cord Pendants. Covers of outlet boxes and
conduit bodies having holes through which flexible cord
pendants pass shall be provided with bushings designed for
the purpose or shall have smooth, well-rounded surfaces on
which the cords may bear. So-called hard rubber or
composition bushings shall not be used.

314.27 Outlet Boxes.

(A) Boxes at Luminaire Outlets. Boxes used at luminaire
or lampholder outlets IE .a celling shall be designed for the
pu^ose iand^shall Jte iaquire^ toj^support a tomin|irei
^weighing a m o]f 23 kg X5,0 ;lb)*„ B^ used ai

|iminair£otJa^^

fe)t file purpoie arid shaj bemiifedb^ interior of tfie

box to indicate, the maxtoum weigM

is permitted tob^ suppojl^ % fe brainthe wall^ if other

pia^'23!kg (50 j^^ At every outlet used exclusively for

lighting, the box shall be designed or installed so that a

luminaire may be attached.

Exception: A wall-mounted luminaire weighing not more
than 3 kg (6 lb) shall be permitted to be supported on other
boxes or plaster rings that are secured to other boxes,
provided the luminaire or its supporting yoke is secured to
the box with no fewer than two No. 6 or larger screws.

70-172

2010 California Electrical Code

ARTICLE 3 14 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES

314.29

(B) Maximum Luminaire Weight Outlet boxes or
fittings 6,migmd for tke supporr of ; tamimires a^^
installed as required by 314.23 shall be permitted to
support aj liumnair^ weighing 23 kg (50 lb) or less. A
luminaire that weighs more than 23 kg (50 lb) shall be
supported independently of the outlet box unless the
outlet box is listed and Marked for the maxiiniini weight
to be supported.

Exception: Where the authority having jurisdiction
judges them free from likely exposure to physical damage,
moisture, and dirt, boxes located in elevated floors of
show windows and similar locations shall be permitted to
be other than those listed for floor applications.
Receptacles and covers shall be listed as an assembly for
this type of location.

(D) Boxes at Ceiling-Suspended (Paddle) Fan Outlets.

Outlet boxes or outlet box systems used as the sole
support of a ceiling-suspended (paddle) fan shall be
listed, shall be marked by their manufacturer as suitable
for this purpose, and shall not support ceiling-suspended
(paddle) fans that weigh more than 32 kg (70 lb). For
outlet boxes or outlet box systems designed to support
ceiling-suspended (paddle) fans that weigh more than 16
kg (35 lb), the required marking shall include the
maximum weight to be supported.

p) Utiililatioii Equipment. Boxes used for th^ support
bf titiiizatioii equipment other than; ceiling-suspendpd
(paddle) fans shkll meet the req^femeMspf 3i4^27(^^^
m6:(B) mt the suppoitofalumii^ake^^
and weigit

Exception: jJtiUzation equipment weighing not more than
'$ kg (6 fb) shall be permitted to be supported on othen

Jyoxes or Iplaster rings that are secured to other boxes,\
irovidedkhe equipment or its supporting yoke is secured

314.28 Pull and Junction Boxes and Conduit Bodies.

Boxes and conduit bodies used as pull or junction boxes
shall comply with 314.28(A) through (D).

Exception: Terminal housings supplied with motors shall
comply with the provisions of 430.12.

(A) Minimum Size. For raceways containing conductors
of 4 AWG or larger |jiat:^e''i;egu^ and

for cables containing conductors of 4 AWG or larger, the
minimum dimensions of pull or junction boxes installed
in a raceway or cable run shall comply with (A)(1)
through (A)(3). Where an enclosure dimension is to be
calculated based on the diameter of entering raceways, the
diameter shall be the metric designator (trade size)
expressed in the units of measurement employed.

(1) Straiglit Pulls. In straight pulls, the length of the box
shall not be less than eight times the metric designator
(trade size) of the largest raceway.

(2) Angle or U Pulls, )^r SpMclesJ Where splices or where
angle or U pulls are made, the distance between each
raceway entry inside the box and the opposite wall of the
box shall not be less than six times the metric designator
(trade size) of the largest raceway in a row. This distance
shall be increased for additional entries by the amount of
the sum of the diameters of all other raceway entries in the
same row on the same wall of the box. Each row shall be
calculated individually, and the single row that provides the
maximum distance shall be used.

Exception: Where a raceway or cable entry is in the wall
of a box or conduit body opposite a removable cover, the
distance from that wall to the cover shall be permitted to
comply with the distance required for one wire per
terminal in Table 312.6(A).

The distance between raceway entries enclosing the
same conductor shall not be less than six times the metric
designator (trade size) of the larger raceway.

When transposing cable size into raceway size in
314.28(A)(1) and (A)(2), the minimum metric designator
(trade size) raceway required for the number and size of
conductors in the cable shall be used.

(3) Smaller Dimensions. Boxes or conduit bodies of
dimensions less than those required in 314.28(A)(1) and
(A)(2) shall be permitted for installations of combinations
of conductors that are less than the maximum conduit or
tubing fill (of conduits or tubing being used) permitted by
Table 1 of Chapter 9, provided the box or conduit body has
been listed for, and is permanently marked with, the
maximum number and maximum size of conductors
permitted.

(B) Conductors in Pull or Junction Boxes. In pull boxes
or junction boxes having any dimension over 1.8 m (6 ft),
all conductors shall be cabled or racked up in an approved
manner.

(C) Covers. All pull boxes, junction boxes, and conduit
bodies shall be provided with covers compatible with the
box or conduit body construction and suitable for the
conditions of use. Where used, metal covers shall comply
with the grounding requirements of 250.1 10.

(D) Permanent Barriers. Where permanent barriers are
installed in a box, each section shall be considered as a
separate box.

314.29 Boxes, Conduit Bodies, and Handhole
Enclosures to Be Accessible. Boxes, conduit bodies, and
handhole enclosures shall be installed so that the wiring

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314.30

ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES

contained in them can be rendered accessible without
removing any part of the building or, in underground
circuits, without excavating sidewalks, paving, earth, or
other substance that is to be used to establish the finished
grade.

Exception: Listed boxes and handhole enclosures shall be
permitted where covered by gravel, light aggregate, or
noncohesive granulated soil if their location is effectively '
identified and accessible for excavation.

314.30 Handhole Enclosures. Handhole enclosures shall
be designed and installed to withstand all loads likely to be
imposed on them. They shall be idetitified for use jt^
imderground systemsi

FPN: See ANSI/SCTE 77-2002, Specification for
Underground Enclosure Integrity, for additional
information on deUberate and nondeliberate traffic loading
that can be expected to bear on underground enclosures.

(A) Size. Handhole enclosures shall be sized in accordance
with 314.28(A) for conductors operating at 600 volts or
below, and in accordance with 314.71 for conductors
operating at over 600 volts. For handhole enclosures
without bottoms where the provisions of 314.28(A)(2),
Excepfion, or 314.71(B)(1), Excepfion No. 1, apply, the
measurement to the removable cover shall be taken from
the end of the conduit or cable assembly.

(B) Wiring Entries. Underground raceways and cable
assemblies entering a handhole enclosure shall extend into
the enclosure, but they shall not be required to be
mechanically connected to the enclosure.

(C) Enclosed Wiring. All enclosed conductors and any
sphces or terminations, if present, shall be listed as suitable
for wet locations.

(D) Covers. Handhole enclosure covers shall have an
identifying mark or logo that prominently identifies the
fimcfion of the enclosure, such as "electric." Handhole
enclosure covers shall require the use of tools to open, or
they shall weigh over 45 kg (100 lb). Metal covers and
other exposed conductive surfaces shall be bonded in
accordance with 250.92(A) if the conductors in the
handhole are service conductors^ or iti accordance with
S50*96(A) if the conductors in the handtole are feeder or
bf anctcircuit conduetdi^^

III. Construction Specifications

314.40 Metal Boxes, Conduit Bodies, and Fittings.

(A) Corrosion Resistant. Metal boxes, conduit bodies, and
fittings shall be corrosion resistant or shall be well-
galvanized, enameled, or otherwise properly coated inside
and out to prevent corrosion.

FPN: See 300.6 for limitation in the use of boxes and
fittings protected from corrosion solely by enamel.

(B) Thiclmess of Metal. Sheet steel boxes not over 1650
cm3 (100 in.3) in size shall be made from steel not less
than 1.59 mm (0.0625 in.) thick. The wall of a malleable
iron box or conduit body and a die-cast or permanent-mold
cast aluminum, brass, bronze, or zinc box or conduit body
shall not be less than 2.38 mm (3/32 in.) thick. Other cast
metal boxes or conduit bodies shall have a wall thickness
not less than 3.17 mm (1/8 in.).

Exception No. I: Listed boxes and conduit bodies shown to
have equivalent strength and characteristics shall be
permitted to be made of thinner or other metals.

Exception No. 2: The walls of listed short radius conduit
bodies, as covered in 314.5, shall be permitted to be made
of thinner metal.

(C) Metal Boxes Over 1650 cm3 (100 in.3). Metal boxes
over 1650 cm3 (100 in.3) in size shall be constructed so as to
be of ample strength and rigidity. If of sheet steel, the metal
thickness shall not be less than 1.35 mm (0.053 in.) uncoated.

(D) Grounding Provisions. A means shall be provided in
each metal box for the connection of an equipment
grounding conductor. The means shall be permitted to be a
tapped hole or equivalent.

314.41 Covers. Metal covers shall be of the same material
as the box or conduit body with which they are used, or
they shall be lined with firmly attached insulating material
that is not less than 0.79 mm (1/32 in.) thick, or they shall
be Hsted for the purpose. Metal covers shall be the same
thickness as the boxes or conduit body for which they are
used, or they shall be Hsted for the purpose. Covers of
porcelain or other approved insulating materials shall be
permitted if of such form and thickness as to afford the
required protecfion and strength.

314.42 Bushings. Covers of outlet boxes and conduit bodies
having holes through which flexible cord pendants may pass
shall be provided with approved bushings or shall have
smooth, well-rounded surfaces on which the cord may bear.
Where individual conductors pass through a metal cover, a
separate hole equipped with a bushing of suitable insulating
material shall be provided for each conductor. Such separate
holes shall be connected by a slot as required by 300.20.

314.43 Nonmetallic Boxes. Provisions for supports or
other mounting means for nonmetallic boxes shall be
outside of the box, or the box shall be constructed so as to
prevent contact between the conductors in the box and the
supporting screws.

314.44 Marking. All boxes and conduit bodies, covers,
extension rings, plaster rings, and the like shall be durably

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2010 California Electrical Code

ARTICLE 320 - ARMORED CABLE: TYPE AC

320.10

and legibly marked with the manufacturer's name or
trademark.

IV. Pull and Junction Boxes for Use on Systems over
600 Volts, Nominal

314.70 General. Where pull and junction boxes are used
on systems over 600 volts, the installation shall comply
with the provisions of Part IV and also with the following
general provisions of this article:

(1) Part I, 314.2, 314.3, and 314.4

(2) Part II, 314.15; 314.17; 314.20; 314.23(A), (B), or (G);
314.28(B); and 3 14.29

(3) Part III, 314.40(A) and (C) and 314.41

314.71 Size of Pull and Junction Boxes. Pull and
junction boxes shall provide adequate space and
dimensions for the installation of conductors, and they shall
comply with the specific requirements of this section.

Exception: Terminal housings supplied with motors shall
comply with the provisions of 430.12.

(A) For Straight Pulls. The length of the box shall not be
less than 48 times the outside diameter, over sheath, of the
largest shielded or lead-covered conductor or cable
entering the box. The length shall not be less than 32 times
the outside diameter of the largest nonshielded conductor
or cable.

(B) For Angle or U Pulls.

(1) Distance to Opposite Wall. The distance between
each cable or conductor entry inside the box and the
opposite wall of the box shall not be less than 36 times the
outside diameter, over sheath, of the largest cable or
conductor. This distance shall be increased for additional
entries by the amount of the sum of the outside diameters,
over sheath, of all other cables or conductor entries through
the same wall of the box.

Exception No. 1: Where a conductor or cable entry is in
the wall of a box opposite a removable cover, the distance
from that wall to the cover shall be permitted to be not less
than the bending radius for the conductors as provided in
300.34.

Exception No. 2: Where cables are nonshielded and not
lead covered, the distance of 36 times the outside diameter
shall be permitted to be reduced to 24 times the outside
diameter.

(2) Distance Between Entry and Exit. The distance
between a cable or conductor entry and its exit from the
box shall not be less than 36 times the outside diameter,
over sheath, of that cable or conductor.

Exception: Where cables are nonshielded and not lead
covered, the distance of 36 times the outside diameter shall
be permitted to be reduced to 24 times the outside
diameter.

314.72 Construction and Installation Requirements.

(A) Corrosion Protection. Boxes shall be made of
material inherently resistant to corrosion or shall be
suitably protected, both internally and externally, by
enameling, galvanizing, plating, or other means.

(B) Passing Through Partitions. Suitable bushings,
shields, or fittings having smooth, rounded edges shall be
provided where conductors or cables pass through
partitions and at other locations where necessary.

(D) Wiring Is Accessible. Boxes shall be installed so that
the wiring is accessible without removing any part of the
building. Working space shall be provided in accordance
with 110.34.

(E) Suitable Covers. Boxes shall be closed by suitable
covers securely fastened in place. Underground box covers
that weigh over 45 kg (100 lb) shall be considered meeting
this requirement. Covers for boxes shall be permanently
marked "DANGER — HIGH VOLTAGE — KEEP OUT."
The marking shall be on the outside of the box cover and
shall be readily visible. Letters shall be block type and at
least 13 mm QA in.) in height.

(F) Suitable for Expected Handling. Boxes and their
covers shall be capable of withstanding the handling to
which they are likely to be subjected.

i^-mored Cable: Type AC

I. General

320.1 Scope. This article covers the use, installation, and
construction specifications for armored cable, Type AC.

320.2 Definition.

Armored Cable, Type AC. A fabricated assembly of
insulated conductors in a flexible metallic enclosure. See
320.100.

II. Installation

320.10 Uses Permitted. Type AC cable shall be permitted
as follows:

(1) Bof^AptimA^ in both exposed and
concealed work

(2) In cable trays

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320.12

ARTICLE 320 - ARMORED CABLE: TYPE AC

(3) In dry locations

(4) Embedded in plaster finish on brick or other masonry,
except in damp or wet locations

(5) To be run or fished in the air voids of masonry block or
tile walls where such walls are not exposed or subject
to excessive moisture or dampness

FPN: The "Uses Permitted" is not an all-inclusive list.

320.12 Uses Not Permitted. Type AC cable shall not be
used as follows:

(1) Where subject to physical damage

(2) In damp or wet locations

(3) In air voids of masonry block or tile walls where such walls

are exposed or subject to excessive moisture or dampness

(4) Where exposed to corrosive fumes or vapors

(5) Embedded in plaster finish on brick or other masonry
in damp or wet locations

320.15 Exposed Work. Exposed runs of cable, except as
provided in 300.11(A), shall closely follow the surface of
the building finish or of running boards. Exposed runs shall
also be permitted to be installed on the underside of joists
where supported at each joist and located so as not to be
subject to physical damage.

320.17 Through or Parallel to Framing Members. Type AC

cable shall be protected in accordance with 300.4(A), (C), and
(D) where installed through or parallel to framing members.

320.23 In Accessible Attics. Type AC cables in accessible
attics or roof spaces shall be installed as specified in
320.23(A) and (B).

(A) Where Run Across the Top of Floor Joists. Where
run across the top of floor joists, or within 2.1 m (7 ft) of
floor or floor joists across the face of rafters or studding, in
attics and roof spaces that are accessible, the cable shall be
protected by substantial guard strips that are at least as high
as the cable. Where this space is not accessible by
permanent stairs or ladders, protection shall only be
required within 1.8 m (6 ft) of the nearest edge of the
scuttle hole or attic entrance.

(B) Cable Installed Parallel to Framing Members. Where

the cable is installed parallel to the sides of rafters, studs, or
floor joists, neither guard strips nor running boards shall be
required, and the installation shall also comply with 300.4(D).

320.24 Bending Radius. Bends in Type AC cable shall be
made such that the cable is not damaged. The radius of the
curve of the inner edge of any bend shall not be less than
five times the diameter of the Type AC cable.

320.30 Securing and Supporting.

(A) General. Type AC cable shall be supported and secured
by staples, cable ties, straps, hangers, or similar fittings,
designed and installed so as not to damage the cable.

(B) Securing. Unless otherwise provided, Type AC cable
shall be secured within 300 mm (12 in.) of every outlet
box, junction box, cabinet, or fitting and at intervals not
exceeding 1.4 m (4/2 ft) where installed on or across
framing members.

Horizontal runs of Type AC cable installed in wooden or
metal framing members or similar supporting means shall
be considered supported where such support does not
exceed 1.4-m (4V2-ft) intervals.

(D) Unsupported Cables. Type AC cable shall be
permitted to be unsupported where the cable complies with
any of the following:

(1) Is fished between ' access points through concealed
spaces in finished buildings or structures and
supporting is impracticable

(2) Is not more than 600 mm (2 ft) in length at terminals
where flexibility is necessary

(3) Is not more than 1.8 m (6 ft) in length from the last
point of cable support to the point of connection to a
luminaire(s) or other electrical equipment and the
cable and point of connection are within an accessible
ceiling. For the purposes of this section. Type AC
cable fittings shall be permitted as a means of cable
support.

320.40 Boxes and Fittings. At all points where the armor
of AC cable terminates, a fitting shall be provided to
protect wires from abrasion, unless the design of the outlet
boxes or fittings is such as to afford equivalent protection,
and, in addition, an insulating bushing or its equivalent
protection shall be provided between the conductors and
the armor. The connector or clamp by which the Type AC
cable is fastened to boxes or cabinets shall be of such
design that the insulating bushing or its equivalent will be
visible for inspection. Where change is made from Type
AC cable to other cable or raceway wiring methods, a box,
fitting, or conduit body shall be installed at junction points
as required in 300. 1 5.

320.80 Ampacity. The ampacity shall be determined by

310.15.

•

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2010 California Electrical Code

ARTICLE 322 - FLAT CABLE ASSEMBLIES: TYPE FC

322.56

(A) Thermal Insulation. Armored cable installed in
thermal insulation shall have conductors rated at 90°C
(194°F). The ampacity of cable installed in these
applications shall be that of 60°C (140°F) conductors. The
90°C (194°F) rating shall be permitted to be used for
ampacity derating purposes, provided the final derated
ampacity does not exceed that for a 60°C (140T) rated
conductor.

(B) Cable Tray. The ampacity of Type AC cable installed in
cable tray shall be determined in accordance with 392. 1 1 .

III. Construction Specifications

320.100 Construction. Type AC cable shall have an
armor of flexible metal tape and shall have an internal
bonding strip of copper or aluminum in intimate contact
with the armor for its entire length.

320.104 Conductors. Insulated conductors shall be of a
type hsted in Table 310.13(A) or those identified for use in
this cable. In addition, the conductors shall have an overall
moisture-resistant and fire-retardant fibrous covering. For
Type ACT, a moisture-resistant fibrous covering shall be
required only on the individual conductors.

320.108 Equipment Grounding Cijuducton Type AC
cable shall provide an adequate path for fault current as

I;equife35y ■25d'4{A)(5) or lB)(4)io'^^^^

320.120 Marking. The cable shall be marked in
accordance with 310.11, except that Type AC shall have
ready identification of the manufacturer by distinctive
external markings on the cable sheath throughout its entire
length.

'l;-:. ARTICLE W^

jiMatCable'Asseiiih

I. General

322.1 Scope. This article covers the use, installafion, and
construction specifications for flat cable assemblies, Type
FC.

322.2 Definition.

Flat Cable Assembly, Type FC. An assembly of parallel
conductors formed integrally with an insulating material
web specifically designed for field installation in surface
metal raceway.

II. Installation

322.10 Uses Permitted. Flat cable assemblies shall be
permitted only as follows:

(1) As branch circuits to supply suitable tap devices for
lighting, small appliances, or small power loads. The
rating of the branch circuit shall not exceed 30
amperes.

(2) Where installed for exposed work.

(3) In locations where they will not be subjected to physical
damage. Where a flat cable assembly is installed less than
2.5 m (8 ft) above the floor or fixed working platform, it
shall be protected by a cover identified for the use.

(4) In surface metal raceways identified for the use. The
channel portion of the surface metal raceway systems
shall be installed as complete systems before the flat
cable assemblies are pulled into the raceways.

322.12 Uses Not Permitted. Flat cable assemblies shall
not be used as follows:

(1) Where subject to corrosive vapors unless suitable for
the application

(2) In hoistways or on elevators or escalators

(3) In any hazardous (classified) location

(4) Outdoors or in wet or damp locations unless identified
for the use

322.30 Securing and Supporting. The flat cable
assemblies shall be supported by means of their special
design features, within the surface metal raceways.

The surface metal raceways shall be supported as
required for the specific raceway to be installed,

322.40 Boxes and Fittings.

(A) Dead Ends. Each flat cable assembly dead end shall be
terminated in an end-cap device identified for the use.

The dead-end fitting for the enclosing surface metal
raceway shall be identified for the use.

(B) Luminaire Hangers. Luminaire hangers installed with
the flat cable assemblies shall be identified for the use.

(C) Fittings. Fittings to be installed with flat cable
assemblies shall be designed and installed to prevent
physical damage to the cable assemblies.

(D) Extensions. All extensions from flat cable assemblies
shall be made by approved wiring methods, within the
junction boxes, installed at either end of the flat cable
assembly runs.

322.56 Splices and Taps.

(A) Splices. Sphces shall be made in listed junction boxes.

(B) Taps. Taps shall be made between any phase conductor
and the grounded conductor or any other phase conductor
by means of devices and fittings identified for the use. Tap
devices shall be rated at not less than 15 amperes, or more

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322.100

ARTICLE 324 - FLAT CONDUCTOR CABLE; TYPE FCC

than 300 volts to ground, and shall be color-coded in
accordance with the requirements of 322.120(C).

III. Construction

322.100 Construction. Flat cable assemblies shall consist
of two, three, four, or five conductors.

322.104 Conductors. Flat cable assemblies shall have
conductors of 10 AWG special stranded copper wires.

322.112 Insulation. The entire flat cable assembly shall be
formed to provide a suitable insulation covering all the
conductors and using one of the materials recognized in
Table 310.13|a5 for general branch-circuit wiring.

322.120 Marking.

(A) Temperature Rating. In addition to the provisions of
3 10. 1 1, Type FC cable shall have the temperature rating
durably marked on the surface at intervals not exceeding
600 mm (24 in.).

(B) Identification of Grounded Conductor. The

grounded conductor shall be identified throughout its
length by means of a distinctive and durable white or gray
marking.

FPN: The color gray may have been used in the past as an
ungrounded conductor. Care should be taken when working
on existing systems.

(C) Terminal Block Identification. Terminal blocks
identified for the use shall have distinctive and durable
markings for color or word coding. The grounded
conductor section shall have a white marking or other
suitable designation. The next adjacent section of the
terminal block shall have a black marking or other suitable
designation. The next section shall have a red marking or
other suitable designation. The final or outer section,
opposite the grounded conductor section of the terminal
block, shall have a blue marking or other suitable
designation.

]'■■■:■:]■■[.. ARTICLE:324;:. ;/.,:^:
Flat €o»ductar Cable: Type FCC

I. General

324.1 Scope. This article covers a field-installed wiring
system for branch circuits incorporating Type FCC cable
and associated accessories as defined by the article. The
wiring system is designed for installation under carpet
squares.

324.2 Definitions.

Bottom Shield. A protective layer that is installed between
the floor and Type FCC flat conductor cable to protect the
cable fi*om physical damage and may or may not be

incorporated as an integral part of the cable.

Cable Connector. A connector designed to join Type FCC
cables without using a junction box.

FCC System. A complete wiring system for branch circuits
that is designed for installation under carpet squares. The FCC
system includes Type FCC cable and associated shielding,
connectors, terminators, adapters, boxes, and receptacles.

Insulating End. An insulator designed to electrically
insulate the end of a Type FCC cable.

Metal Shield Connections. Means of connection designed
to electrically and mechanically connect a metal shield to
another metal shield, to a receptacle housing or self-
contained device, or to a transition assembly.

Top Shield. A grounded metal shield covering under-
carpet components of the FCC system for the purposes of
providing protection against physical damage.

Transition Assembly. An assembly to facilitate
connection of the FCC system to other wiring systems,
incorporating (1) a means of electrical interconnection and
(2) a suitable box or covering for providing electrical safety
and protection against physical damage.

Type FCC Cable. Three or more flat copper conductors
placed edge-to-edge and separated and enclosed within an
insulating assembly.

324.6 Listing Requirements. Type FCC cable and
associated fittings shall be listed.

II. Installation
324.10 Uses Permitted.

(A) Branch Circuits. Use of FCC systems shall be
permitted both for general-purpose and apphance branch
circuits and for individual branch circuits.

(B) Branch-Circuit Ratings.

(1) Voltage. Voltage between ungrounded conductors
shall not exceed 300 volts. Voltage between ungrounded
conductors and the grounded conductor shall not exceed
150 volts.

(2) Current. General-purpose and appliance branch
circuits shall have ratings not exceeding 20 amperes.
Individual branch circuits shall have ratings not exceeding
30 amperes.

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ARTICLE 324 - FLAT CONDUCTOR CABLE: TYPE FCC

324.56

(C) Floors. Use of FCC systems shall be permitted on
hard, sound, smooth, continuous floor surfaces made of
concrete, ceramic, or composition flooring, wood, and
similar materials,

(D) Walls. Use of FCC systems shall be permitted on wall
surfaces in surface metal raceways.

(E) Damp Locations. Use of FCC systems in damp
locations shall be permitted.

(F) Heated Floors. Materials used for floors heated in
excess of 30°C (86°F) shall be identified as suitable for use
at these temperatures.

(G) System Height. Any portion of an FCC system with a
height above floor level exceeding 2.3 mm (0.090 in.) shall
be tapered or feathered at the edges to floor level.

324.12 Uses Not Permitted. FCC systems shall not be
used in the following locations:

(1) Outdoors or in wet locations

(2) Where subject to corrosive vapors

(3) In any hazardous (classified) location

(4) In residential, school, and hospital buildings

324.18 Crossings. Crossings of more than two Type FCC
cable runs shall not be permitted at any one point.
Crossings of a Type FCC cable over or under a flat
communications or signal cable shall be permitted. In each
case, a grounded layer of metal shielding shall separate the
two cables, and crossings of more than two flat cables shall
not be permitted at any one point.

324.30 Securing and Supporting. All FCC system
components shall be firmly anchored to the floor or wall
using an adhesive or mechanical anchoring system
identified for this use. Floors shall be prepared to ensure
adherence of the FCC system to the floor until the carpet
squares are placed.

324.40 Boxes and Fittings.

(A) Cable Connections and Insulating Ends. All Type
FCC cable connections shall use connectors identified for
their use, installed such that electrical continuity,
insulation, and sealing against dampness and liquid spillage
are provided. All bare cable ends shall be insulated and
sealed against dampness and liquid spillage using listed
insulating ends.

(B) Polarization of Connections. All receptacles and
connections shall be constructed and installed so as to
maintain proper polarization of the system.

(1) Top Shield. A metal top shield shall be installed over
all floor-mounted Type FCC cable, connectors, and
insulating ends. The top shield shall completely cover all
cable runs, comers, connectors, and ends.

(2) Bottom Shield. A bottom shield shall be installed
beneath all Type FCC cable, connectors, and insulating
ends.

(D) Connection to Other Systems. Power feed, grounding
connection, and shield system connection between the FCC
system and other wiring systems shall be accomplished in a
transition assembly identified for this use.

(E) Metal-Shield Connectors. Metal shields shall be
connected to each other and to boxes, receptacle housings,
self-contained devices, and transition assemblies using
metal-shield connectors.

324.41 Floor Coverings. Floor-mounted Type FCC cable,
cable connectors, and insulating ends shall be covered with
carpet squares not larger than 914 mm (36 in.) square.
Carpet squares that are adhered to the floor shall be
attached with release-type adhesives.

324.42 Devices.

(A) Receptacles. All receptacles, receptacle housings, and
self-contained devices used with the FCC system shall be
identified for this use and shall be connected to the Type
FCC cable and metal shields. Connection from any
grounding conductor of the Type FCC cable shall be made
to the shield system at each receptacle.

(B) Receptacles and Housings. Receptacle housings and
self-contained devices designed either for floor mounting
or for in- wall or on- wall mounting shall be permitted for
use with the FCC system. Receptacle housings and self-
contained devices shall incorporate means for facilitating
entry and termination of Type FCC cable and for
electrically connecting the housing or device with the metal
shield. Receptacles and self-contained devices shall comply
with 406.3. Power and communications outlets installed
together in common housing shall be permitted in
accordance with 800.133(A)(1)(c), Exception No. 2.

324.56 Splices and Taps.

(A) FCC Systems Alterations. Alterations to FCC
systems shall be permitted. New cable connectors shall be
used at new connection points to make alterations. It shall
be permitted to leave unused cable runs and associated
cable connectors in place and energized. All cable ends
shall be covered with insulating ends.

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324.60

ARTICLE 326 - INTEGRATED GAS SPACER CABLE: TYPE IGS

(B) Transition Assemblies. All transition assemblies shall
be identified for their use. Each assembly shall incorporate
means for facilitating entry of the Type FCC cable into the
assembly, for connecting the Type FCC cable to grounded
conductors, and for electrically connecting the assembly to
the metal cable shields and to equipment grounding
conductors.

324.60 Grounding. All metal shields, boxes, receptacle
housings, and self-contained devices shall be electrically
continuous to the equipment grounding conductor of the
supplying branch circuit. All such electrical connections shall
be made with connectors identified for this use. The electrical
resistivity of such shield system shall not be more than that of
one conductor of the Type FCC cable used in the installation.

III. Construction

324.100 Construction.

(A) Type FCC Cable. Type FCC cable shall be listed for
use with the FCC system and shall consist of three, four, or
five flat copper conductors, one of which shall be an
equipment grounding conductor.

(B) Shields.

(1) Materials and Dimensions. All top and bottom
shields shall be of designs and materials identified for their
use. Top shields shall be metal. Both metallic and
nonmetallic materials shall be permitted for bottom shields.

(2) Resistivity. Metal shields shall have cross-sectional
areas that provide for electrical resistivity of not more than
that of one conductor of the Type FCC cable used in the
installation.

324.101 Corrosion Resistance. Metal components of the
system shall be either corrosion resistant, coated with
corrosion-resistant materials, or insulated from contact with
corrosive substances.

324.112 Insulation. The insulating material of the cable
shall be moisture resistant and flame retardant. All
insulating materials in the FCC systems shall be identified
for their use.

324.120 Markings.

(A) Cable Marking. Type FCC cable shall be clearly and
durably marked on both sides at intervals of not more than
610 mm (24 in.) with the information required by
310.1 1(A) and with the following additional information:

( 1 ) Material of conductors

(2) Maximum temperature rating

(3) Ampacity

(B) Conductor Identification. Conductors shall be clearly
and durably identified on both sides throughout their length
as specified in 310.12.

^i;V:r;:;^RTIGLE 326,; \.:^/:"r\^ '
Integrated Gas Spacer Cable: T^e IGS

I. General

326.1 Scope. This article covers the use, installation, and
construction specifications for integrated gas spacer cable,
Type IGS.

326.2 Definition.

Integrated Gas Spacer Cable, Type IGS. A factory
assembly of one or more conductors, each individually
insulated and enclosed in a loose fit, nonmetallic flexible
conduit as an integrated gas spacer cable rated through
600 volts.

II. Installation

326.10 Uses Permitted. Type IGS cable shall be permitted
for use under ground, including direct burial in the earth, as
the following:

(1) Service-entrance conductors

(2) Feeder or branch-circuit conductors

326.12 Uses Not Permitted. Type IGS cable shall not be
used as interior wiring or be exposed in contact with
buildings.

326.24 Bending Radius. Where the coilable nonmetallic
conduit and cable is bent for installation purposes or is
flexed or bent during shipment or installation, the radii of
bends measured to the inside of the bend shall not be less
than specified in Table 326.24.

Table 326.24 Minimum Radii of Bends

Conduit Size

Minimum Radii

Metric Designator

Trade Size

mm in.

600 24

900 35

103

1150 45

326.26 Bends. A run of Type IGS cable between pull
boxes or terminations shall not contain more than the
equivalent of four quarter bends (360 degrees total),
including those bends located immediately at the pull box
or terminations.

326.40 Fittings. Terminations and sphces for Type IGS
cable shall be identified as a type that is suitable for
maintaining the gas pressure within the conduit. A valve
and cap shall be provided for each length of the cable and
conduit to check the gas pressure or to inject gas into the
conduit.

70-180

2010 California Electrical Code

ARTICLE 328 - MEDIUM VOLTAGE CABLE: TYPE MV

328.80

326.80 Ampacity. The ampacity of Type IGS cable shall
not exceed the values shown in Table 326.80.

Table 326.80

Ampacity of Type IGS Cable

Size (kcmil)

Amperes

Size (kcmil)

Amperes

250

119

2500

376

500

168

3000

412

750

206

3250

429

1000

238

3500

445

1250

266

3750

461

1500

292

4000

476

1750

315

4250

491

2000

336

4500

505

2250

357

4750

519

in. Construction Specifications

326.104 Conductors. The conductors shall be solid

aluminum rods, laid parallel, consisting of one to nineteen

12.7 mm (Y2 in.) diameter rods. The minimum conductor

size shall be 250 kcmil, and the maximum size shall be

4750 kcmil.

326.112 Insulation. The insulation shall be dry kraft paper

tapes and a pressurized sulfur hexafluoride gas (SFe), both

approved for electrical use. The nominal gas pressure shall

be 138 kPa gauge (20 pounds per square inch gauge). The

thickness of the paper spacer shall be as specified in Table

326.112.

Table 326.112 Paper Spacer Thickness

Thickness

Size (kcmil)

in.

250-1000

1250-4750

1.02
1.52

0.040
0.060

326.116 Conduit. The conduit shall be a medium density
polyethylene identified as suitable for use with natural gas
rated pipe in metric designator 53, 78, or 103 (trade size 2,
3, or 4). The percent fill dimensions for the conduit are
shown in Table 326.1 16.

The size of the conduit permitted for each conductor size
shall be calculated for a percent fill not to exceed those
found in Table 1, Chapter 9.
Table 326.116 Conduit Dimensions

Conduit Size

Actual Outside
Diameter

Actual Inside
Diameter

Metric

Trade

Designator

Size

in.

2.375

49.46

1.947

3.500

73.30

2.886

103

114

4.500

94.23

3.710

:J:';;:^j:\--MeitM^ Type:MV. ;': i'-i

I. General

328.1 Scope. This article covers the use, installation,
and construction specifications for medium voltage
cable, Type MV.

328.2 Definition.

Medium Voltage Cable, Type MV. A single or
multiconductor solid dielectric insulated cable rated 2001
volts or higher.

II. Installation

328.10 Uses Permitted. Type MV cable shall be permitted
for use on power systems rated up to 35,000 volts nominal
as follows:

(1) In wet or dry locations

(2) In raceways

(3) fn\ ^aEle Srays, where „ identified for^ t^^ ras6, ih;
fe<?Prdance^y92^

326.120 Marking. The cable shall be marked in
accordance with 310.11(A), 310.11(B)(1), and 310.1 1(D).

Exception: ^Type^ MV^bhlkai has an overatV metallic
^sheath of jirinor, also complies; with the requirements for
yfype MCcabhyand is identified as . '\MV or MCXsHallbk
permHted to, be in^taHedin cable trays ih accordance j^itti

M2,mmM '" "' '^^ ^^'"" ' ""^""^

(4) Direct buried in accordance with 300.50

(5) In messenger-supported wiring ^§ccQ^<^r^'6 wiih^^fB^

(6) [p^?$osjeffT55rfi5^^

Exception: Typ!Bi^J^fV xdble that; has an overall metalEo,
Wteath pr^armpK'alsocd^ the requirements fori

^'ypeMC cabled dfki is t MC'- shall bi

perinitt^d /d. 'be'' instuUed \gs^ ^^posed jwtsgfjnefql^clad
'cable' in accprdgnce, yyjth:300J74

FPN: The ''Uses Permitted" is not an all-inclusive list.
328.12 Uses Not Permitted.^^^T^^ not be

usedjWhere exposed to direct sunlight iiiiless ^ identified fo^
theusgi

328.80 Ampacity. The ampacity of Type MV cable shall
be determined in accordance with 310.60. The ampacity of
Type MV cable installed in cable tray shall be determined
in accordance with 392.13.

III. Construction Specifications

328.100 Construction. Type MV cables shall have
copper, aluminum, or copper-clad aluminum conductors
and shall comply with Table ;5rO:i3(C) and Table
310.13(D) or Table 310.13(E).

328.120 Marking. Medium voltage cable shall be marked
as required by 310.11.

2010 California Electrical Code

70-181

328.100

ARTICLE 330 - METAL-CLAD CABLE: TYPE MC

ARTICLE 330

Metal-Clad Cable: f ype MC

L General

330.1 Scope. This article covers the use, installation, and
construction specifications of metal-clad cable, Type MC.

330.2 Definition.

Metal Clad Cable, Type MC. A factory assembly of one or
more insulated circuit conductors with or without optical
fiber members enclosed in an armor of interlocking metal
tape, or a smooth or corrugated metallic sheath.

II. Installation

330.10 Uses Permitted.

(A) General Uses. Type MC cable shall be permitted as
follows:

(1) For services, feeders, and branch circuits

(2) For power, lighting, control, and signal circuits

(3) Indoors or outdoors

(4) Exposed or concealed

(5) To be direct buried where identified for such use

(6) In cable tray where identified for such use

(7) In any raceway

(8) As aerial cable on a messenger

(9) In hazardous (classified) locations as permitted

(10) In dry locations and embedded in plaster finish on
brick or other masonry except in damp or wet locations

(11) In wet locations where any of the following
conditions are met:

a. The metallic covering is impervious to moisture.

b. A lead sheath or moisture-impervious jacket is

provided under the metal covering.

c. The insulated conductors under the metallic

covering are listed for use in wet locations and a
corrosion-resistant jacket is provided oyer the
metallic sheath.

(12) Where single-conductor cables are used, all phase
conductors and, where used, the neutral conductor
shall be grouped together to minimize induced voltage
on the sheath.

(B) Specific Uses. Type MC cable shall be permitted to be
installed in compliance with Parts II and III of Article 725
and 770.133 as applicable and in accordance with
330.10(B)(1) through (B)(4).

(1) Cable Tray. Type MC cable installed in cable tray shall
comply with 392.3, 392.4, 392.6, and 392.8 through 392.13.

(2) Direct Buried. Direct-buried cable shall comply with
300.5 or 300.50, as appropriate.

(3) Installed as Service-Entrance Cable. Type MC cable
installed as service-entrance cable shall be permitted in
accordance with 230.43.

(4) Installed Outside of Buildings oiv Striietjure^^ or as
Aerial Cable. Type MC cable installed outside of
buildings |ojr ;staciures or as aerial cable shall comply with
225.10, 396.10, and 396.12.

FPN: The "Uses Pennitted" is not an all-inclusive list.

330.12 Uses Not Permitted^ Type MC cable shall not be

used ||g||er;qiffi^ oM|^||loWing,i^^

(1) Where subject to physical damage

(2) Where exposed to| any qf the destructive corrosiye
conditions m j[a) or (h% .M§k^jJt%. J?i?!,^fU?. ,^^?§ft, or
armoris resista.nt to 5ie COT protected by
materialresistaht to the conditions:

Direct buried in the earth or embedded in con^^
unless identified^r direct^to

Exposed to cinder fills, strong chlorides, caustic,
^jkalis^ or vapors of chlorine or of hydrochloric acidd

330.17 Through or Parallel to Framing Members. Type MC
cable shall be protected in accordance with 300.4(A), (C), and
(D) where installed through or parallel to framing members.

330.23 In Accessible Attics. The installation of Type MC
cable in accessible attics or roof spaces shall also comply
with 320.23.

330.24 Bending Radius. Bends in Type MC cable shall be
so made that the cable will not be damaged. The radius of
the curve of the inner edge of any bend shall not be less
than required in 330.24(A) through (C).

(A) Smooth Sheath.

(1) Ten times the extemal diameter of the metallic sheath for
cable not more than 19 mm (% in.) in extemal diameter

(2) Twelve times the extemal diameter of the metalHc sheath
for cable more than 19 mm (Va in.) but not more than 38
mm (1/4 in.) in extemal diameter

70-182

2010 California Electrical Code

ARTICLE 330 ~ METAL-CLAD CABLE: TYPE MC

330.116

(3) Fifteen times the external diameter of the metaUic sheath
for cable more than 38 mm (IVi in.) in external diameter

(B) Interlocked-Type Armor or Corrugated Sheath.

Seven times the external diameter of the metallic sheath.

(C) Shielded Conductors. Twelve times the overall diameter
of one of the individual conductors or seven times the overall
diameter of the multiconductor cable, whichever is greater.

330.30 Securing and Supporting.

(A) General. Type MC cable shall be supported and
secured by staples, cable ties, straps, hangers, or similar
fittings or other approved means designed and installed so
as not to damage the cable.

(B) Securing. Unless otherwise provided, cables shall be
secured at intervals not exceeding 1.8 m (6 ft). Cables
containing four or fewer conductors sized no larger than 10
AWG shall be secured within 300 mm (12 in.) of every
box, cabinet, fitting, or other cable termination.

Horizontal runs of Type MC cable installed . in wooden or
metal framing members or similar supporting means shall
be considered supported and secured where such support
does not exceed 1.8-m (6-ft) intervals.

(D) Unsupported Cables. Type MC cable shall be
permitted to be unsupported where the cable:

(1) Is fished between access points through concealed
spaces in finished buildings or structures and
supporting is impractical; or

(2) Is not more than 1.8 m (6 ft) in length fi-om the last
point of cable support to the point of connection to
luminairej or other electrical equipment and the cable
and point of connection are within an accessible
ceiling. For the purpose of this section, Type MC cable
fittings shall be permitted as a means of cable support.

330.31 Single Conductors. Where single-conductor
cables with a nonferrous armor or sheath are used, the
installation shall comply with 300.20.

330.40 Boxes and Fittings. Fittings used for connecting
Type MC cable to boxes, cabinets, or other equipment shall
be listed and identified for such use.

330.80 Ampacity. The ampacity of Type MC cable shall
be detennined in accordance with 310.15 or 310.60 for 14
AWG and larger conductors and in accordance with Table
402.5 for 18 AWG and 16 AWG conductors. The
installation shall not exceed the temperature ratings of
terminations and equipment.

(A) Type MC Cable Installed in Cable Tray. The

ampacities for Type MC cable installed in cable tray shall
be determined in accordance with 392. II and 392. 13.

(B) Single Type MC Conductors Grouped Together.

Where single Type MC conductors are grouped together in
a triangular or square configuration and installed on a
messenger or exposed with a maintained free airspace of
not less than 2.15 times one conductor diameter (2.15 x
O.D.) of the largest conductor contained within the
configuration and adjacent conductor configurations or
cables, the ampacity of the conductors shall not exceed the
allowable ampacities in the following tables:

(1) Table 310.20 for conductors rated through 2000 volts

(2) Table 310.67 and Table 310.68 for conductors rated over
2000 vohs

III. Construction Specifications

330.104 Conductors. Conductors shall be of copper,

aluminum, copper-clad aluminum, nipkej. -0^ nickelrC-oateS
itoppetj, solid or stranded. The minimum conductor size
shall be 18 AWG copper, mckgl^jr^yMckg
and 12 AWG aluminum or copper-clad aluminum.

330.108 Equipment Grounding Coiiductor. Where Type
MC cable is used to provide m equipment grounding
conductorj it shall comply with 250.1 18(10) and 250. 122.

330.112 Insulation. Insulated conductors shall comply
with 330.1 12(A) or (B).

(A) 600 Volts. Insulated conductors in sizes 18 AWG and
16 AWG shall be of a type listed in Table 402.3, with a
maximum operating temperature not less than 90°C
(194°F).and as permitted by 725.49. Conductors larger than
16 AWG shall be of a type listed in Table 310.13(A) or of a
type identified for use in Type MC cable.

(B) Over 600 Volts. Insulated conductors shall be of a type
Hsted in Table 310.13(C) through Table 310.13(E).

330.116 Sheath. Metallic covering shall be one of the
following types: smooth metallic sheath, corrugated
metallic sheath, interlocking metal tape armor. The metallic
sheath shall be continuous and close fitting. A nonmagnetic
sheath or armor shall be used on single conductor Type
MC. Supplemental protection of an outer covering of
corrosion-resistant material shall be permitted and shall be
required where such protection is needed. The sheath shall
not be used as a current-carrying conductor.

FPN: See 300.6 for protection against corrosion.

2010 California Electrical Code

70-183

332.1

ARTICLE 332 ~ MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI

ARTICLE 332

Mineral-Insulated^ Metal-Sheathed
Gable: Type MI

I. General

332.1 Scope. This article covers the use, installation, and
construction specifications for mineral-insulated, metal-
sheathed cable. Type MI.

332.2 Definition.

Mineral-Insulated, Metal-Sheathed Cable, Type MI. A factory
assembly of one or more conductors insulated with a highly
compressed refectory mineral insulation and enclosed in a
hquidtight and gastight continuous copper or alloy steel sheath.

II. Installation

332.10 Uses Permitted. Type MI cable shall be permitted
as follows:

(1) For services, feeders, and branch circuits

(2) For power, Hghting, control, and signal circuits

(3) In dry, wet, or continuously moist locations

(4) Indoors or outdoors

(5) Where exposed or concealed

(6) Where embedded in plaster, concrete, fill, or other

masonry, whether above or below grade

(7) In any hazardous (classified) location

(8) Where exposed to oil and gasoHne

(9) Where exposed to corrosive conditions not

deteriorating to its sheath

(10) In underground runs where suitably protected against

physical damage and corrosive conditions

(11) In or attached to cable tray

FPN: The "Uses Permitted" is not an all-inclusive list.

332.12 Uses Not Permitted. Type MI cable shall not be
used under the following conditions or in the following
locations:

(1) In underground runs unless protected from physical
damage, where necessary

(2) Where exposed to conditions that are destructive and
corrosive to the metallic sheath, unless additional
protection is provided

332.17 Through or Parallel to Framing Members. Type
MI cable shall be protected in accordance with 300.4 where
installed through or parallel to framing members.

332.24 Bending Radius. Bends in Type MI cable shall be so
made that the cable will not be damaged. The radius of the inner
edge of any bend shall not be less than required as follows:

(1) Five times the external diameter of the metalhc sheath
for cable not more than 19 mm (Va in.) in external
diameter

(2) Ten times the external diameter of the metalUc sheath
for cable greater than 19 mm (Va in.) but not more than
25 mm (1 in.) in external diameter

332.30 Securing and Supporting. Type MI cable shall be
supported and secured by staples, straps, hangers, or
similar fittings, designed and installed so as not to damage
the cable, at intervals not exceeding 1.8 m (6 ft).

(A) Horizontal Runs Through Holes and Notches. In

other than vertical runs, cables installed in accordance with
300.4 shall be considered supported and secured where
such support does not exceed 1.8 m (6 ft) intervals.

(B) Unsupported Cable. Type MI cable shall be permitted
to be unsupported where the cable is fished between access
points through concealed spaces in finished buildings or
structures and supporting is impracticable.

332.31 Single Conductors. Where single-conductor
cables are used, all phase conductors and, where used, the
neutral conductor shall be grouped together to minimize
induced voltage on the sheath.

332.40 Boxes and Fittings.

(A) Fittings. Fittings used for connecting Type MI cable to
boxes, cabinets, or other equipment shall be identified for
such use.

(B) Terminal Seals. Where Type MI cable terminates, an
end seal fitting shall be installed immediately after
stripping to prevent the entrance of moisture into the
insulation. The conductors extending beyond the sheath
shall be individually provided with an insulating material.

332.80 Ampacity. The ampacity of Type MI cable shall be
determined in accordance with 310.15. The conductor
temperature at the end seal fitting shall not exceed the
temperature rating of the listed end seal fitting, and the
installation shall not exceed the temperature ratings of
terminations or equipment.

70-184

2010 California Electrical Code

ARTICLE 334 - NONMETALLIC- SHEATHED CABLE: TYPES NM, NMC, AND NMS

334.10

(A) Type MI Cable Installed in Cable Tray. The

ampacities for Type MI cable installed in cable tray shall
be determined in accordance with 392. 1 1 .

(B) Single Type MI Conductors Grouped Together.

Where single Type MI conductors are grouped together in
a triangular or square configuration, as required by 332.31,
and installed on a messenger or exposed with a maintained
free air space of not less than 2.15 times one conductor
diameter (2.15 x O.D.) of the largest conductor contained
within the configuration and adjacent conductor
configurations or cables, the ampacity of the conductors
shall not exceed the allowable ampacities of Table 310.17.

III. Construction Specifications

332.104 Conductors. Type MI cable conductors shall be
of solid copper, nickel, or nickel-coated copper with a
resistance corresponding to standard AWG and kcmil sizes.

332.108 Equipment Grounding Conductor* Where the
outer sheath js 5^de of copper, jt shall provide an adequate
path Ip s^0 as a^ condmctar. Wher^|

jiie ;0Uter |t&^ ofste^l^ a separate equipment

grounding conductor shall be provided.

332.112 Insulation. The conductor insulation in Type MI
cable shall be a highly compressed refractory mineral that
provides proper spacing for all conductors.

332.116 Sheath. The outer sheath shall be of a continuous
construction to provide mechanical protection and moisture
seal.

'ARfflGljE:334^^

Nonilietallic-Sheathed Cable: Types NM,

L General

334.1 Scope. This article covers the use, installation, and
construction specifications of nonmetaUic-sheathed cable.

334.2 Definitions.

Nonmetallic -Sheathed Cable. A factory assembly of two or
more insulated conductors enclosed within an overall
nonmetallic jacket.

Type NM. Insulated conductors enclosed within an overall
nonmetallic jacket.

Type NMC. Insulated conductors enclosed within an

overall, corrosion resistant, nonmetallic jacket.

Type NMS. Insulated power or control conductors with

signaling, data, and communications conductors within an

overall nonmetallic jacket.

334.6 Listed. Type NM, Type NMC, and Type NMS

cables shall be listed.

11. Installation

334.10 Uses Permitted. Type NM, Type NMC, and Type
NMS cables shall be permitted to be used in the following:

(1) One- and two-family dwellings.

(2) Multifamily dwellings permitted to be of Types III, IV,
and V construction except as prohibited in 334.12.

(3) Other structures permitted to be of Types III, IV, and V
construction except as prohibited in 334.12. Cables
shall be concealed within walls, floors, or ceilings that
provide a thermal barrier of material that has at least a
15 -minute finish rating as identified in hstings of fire-
rated assemblies.

FPN No. 1: Types of building construction and occupancy
classifications are defined in NFPA 220-1999, Standard on C
Types of Building Construction, or the applicable building A
code, or both.

FPN No. 2: See Annex E for determination of building
types [NFPA 220, Table 3-1].

(4) Cable trays in structures permitted to be Types III, IV,
or V where the cables are identified for the use.

FPN: See 310.10 for temperature limitation of conductors.

Note: [HCD 1 and HCD 2] Types III, IV, and V construction as q
referenced in Section 334.10 items (2), (3), and (4) shall be as f^
defined in Title 24, Part 2, California Building Code. q

(A) Type NM. Type NM cable shall be permitted as
follows:

(1) For both exposed and concealed work in normally dry
locations except as prohibited in 334.10(3)

(2) To be installed or fished in air voids in masonry block
or tile walls

(B) Type NMC. Type NMC cable shall be permitted as
follows:

(1) For both exposed and concealed work in dry, moist,
damp, or corrosive locations, except as prohibited by
334.10(3)

(2) In outside and inside walls of masonry block or tile

(3) In a shallow chase in masonry, concrete, or adobe
protected against nails or screws by a steel plate at
least 1.59 mm (1/16 in.) thick and covered with
plaster, adobe, or similar finish

(1) For both exposed and concealed work in normally dry
locations except as prohibited by 334.10(3)

(2) To be installed or fished in air voids in masonry block
or tile walls

334.12 Uses Not Permitted.

(A) Types NM, NMC, and NMS. Types NM, NMC, and
NMS cables shall not be permitted as follows:

(1) In any dwelling or structure not specifically permitted
in 334,10(1), (2), and (3)

2010 California Electrical Code

70-185

334.12

ARTICLE 332 - MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI

Exception: 'fyp^:^NM,^^ NMQJgnd ^ -NMS cable shall be
perfniked in f^ when instalied

'Within raceways permitted id %e instaJled in Type I and U
cgnstructipn.

C Note: [HCD 1 and HCD 2] Types I and II construction as
A referenced in Section 334.12 item(l) Exception shall be as
C defined in Title 24, Part 2, California Building Code.

(2) Exposed in dropped or suspended ceilings in other than
one- and two- family and multifamily dwellings

(3) As service-entrance cable

(4) In commercial garages having hazardous (classified)
locations as defined in 51:13

(5) In theaters and similar locations, except where

permitted in 5 18.4(B)

(6) In motion picture studios

(7) In storage battery rooms

(8) In hoistways or on elevators or escalators

(9) Embedded in poured cement, concrete, or aggregate

(10) In hazardous (classified) locations, except where
permitted by the following:

a. 501.10(B)(3)

b. 502.10(B)(3)

c. 504.20

(B) Types NM and NMS. Types NM and NMS cables
shall not be used under the following conditions or in the
following locations:

(1) Where exposed to corrosive fumes or vapors

(2) Where embedded in masonry, concrete, adobe, fill, or
plaster

(3) In a shallow chase in masonry, concrete, or adobe and
covered with plaster, adobe, or similar finish

(4) In w# or darnp locations

334.15 Exposed Work. In exposed work, except as
provided in 300.11(A), cable shall be installed as specified
in 334.15(A) through (C).

(A) To Follow Surface. Cable shall closely follow the
surface of the building finish or of running boards.

(B) Protection from Physical Damage. Cable shall be
protected from physical damage where necessary by rigid
metal conduit, intermediate metal conduit, electrical
metallic tubing, Schedule 80 PVC conduit, or other
approved means. Where passing through a floor, the cable
shall be enclosed in rigid metal conduit, intermediate metal
conduit, electrical metallic tubing. Schedule 80 PVC

conduit, or other approved means extending at least 150
mm (6 in.) above the floor.

Type NMC cable installed in shallow chases pr
grooves, in masonry, concrete, or adobe, shall be protected
m accc^dancej^vjffih and

covered with plaster, adobe, or similar finish.

^i^d crawt 'Sp^^^^^ it shall be permissible to secure cables
not smaller than two 6 AWG or three 8 AWG conductors
directly to the lower edges of the joists. Smaller cables
shall be run either through bored holes in joists or on
running boards. NM cable installed on the wall of an
unfinished basement shall be permitted to be installed in a
listed conduit or tubing or jshall be protected in accordance
with 30(X4- Conduit or tubing shall be provided with a
smtabk imuiatmg bushing or adapter at the point the cable
enters the raceway. Jhe NM cable sheath shall extend
through the conduit o4 tubing; and into the outlet or device
box not less than 6 m The cable shall be secured

;witMn3W nm ^^ where the cable enters

the con^^ Metal conduit, tubing, and metal

outlet boxes shall be c|>nnected to aii equipment grounding
conductor^: ^^

334.17 Through or Parallel to Framing Members, ^^w

Types NM, NMC, or NMS cable shall be protected in
accordance with 300.4 where installed through or parallel
to framing members. Grommets used as required in
300.4(B)(1) shall remain in place and be listed for the
purpose of cable protection.

334.23 In Accessible Attics. The installation of cable in
accessible attics or roof spaces shall also comply with

320.23.

334.24 Bending Radius. Bends in Types NM, NMC, and
NMS cable shall be so made that the cable will not be
damaged. The radius of the curve of the inner edge of any
bend during or after installation shall not be less than five
times the diameter of the cable.

334.30 Securing and Supporting. Nonmetallic-sheathed
cable shall be supported and secured by staples, cable ties,
straps, hangers, or similar fittings designed and installed so
as not to damage the cable, at intervals not exceeding 1 .4 m
(4V2 ft) and within 300 mm (12 in.) of every outlet box,
junction box, cabinet, or fitting. Flat cables shall not be
stapled on edge.

Sections of cable protected from physical damage by
raceway shall not be required to be secured within the
raceway.

70-186

2010 California Electrical Code

ARTICLE 334 - NONMETALLIC-SHEATHED CABLE: TYPES NM, NMC, AND NMS

334.116

(A) Horizontal Runs Through Holes and Notches. In

other than vertical runs, cables installed in accordance with
300.4 shall be considered to be supported and secured
where such support does not exceed 1.4-m (4V2-ft) intervals
and the nonmetallic-sheathed cable is securely fastened in
place by an approved means within 300 mm (12 in.) of
each box, cabinet, conduit body, or other nonmetallic-
sheathed cable termination.

FPN: See 314.17(C) for support where nonmetallic boxes
are used.

(B) Unsupported Cables. Nonmetallic-sheathed cable
shall be permitted to be unsupported where the cable:

(1) Is fished between access points through concealed
spaces in finished buildings or structures and
supporting is impracticable.

(2) Is not more than 1.4 m (4/4 ft) from the last point of
cable support to the point of connection to a luminaire
or other piece of electrical equipment and the cable
and point of connection are within an accessible
ceiling.

wiring device identified for the use, without a separate
outlet box, and incorporating an integral cable clamp shall
be permitted where the cable is secured in place at intervals
not exceeding 1.4 m (4!/2 ft) and within 300 mm (12 in.)
from the wiring device wall opening, and there shall be at
least a 300 mm (12 in.) loop of unbroken cable or 150 mm
(6 in.) of a cable end available on the interior side of the
finished wall to permit replacement.

334.40 Boxes and Fittings.

(A) Boxes of Insulating Material. Nonmetallic outlet
boxes shall be permitted as provided by 314.3.

(B) Devices of Insulating Material; Switch, outlet, and tap
devices of insulating material shall be permitted to be used
without boxes in exposed cable wiring and for rewiring in
existing buildings where the cable is concealed and fished.
Openings in such devices shall form a close fit around the
outer covering of the cable, and the device shall frilly
enclose the part of the cable from which any part of the
covering has been removed. Where connections to
conductors are by binding-screw terminals, there shall be
available as many terminals as conductors.

(C) Devices with Integral Enclosures. Wiring devices
with integral enclosures identified for such use shall be
permitted as provided by 300.15(E).

334.80 Ampacity. The ampacity of Types NM, NMC, and
NMS cable shall be determined in accordance with 310.15.
The ampacity shall be in accordance with the 60^C (HO'^F)

conductor temperature rating. The 90°C (194°F) rating
shall be permitted to be used for ampacity derating
purposes, provided the final derated ampacity does not
exceed that for a 60°C (140°F) rated conductor. The
ampacity of Types NM, NMC, and NMS cable installed in
cable tray shall be determined in accordance with 392. 1 1 .

Where more than two NM cables containing two or
more current-carrying conductors are iBStaited^i^TOltiQUt

ppening in[ wood framing that is to be fire- or draft-stopped
using thermal insulation, cautfc^ or sealing foam, the
allowable ampacity of each conductor shall be adjusted in
accordance with Table 310.15(B)(2)(a) knd thepTOvimom

bf 3 j p. j;5(A)(2),^ Exc^^

jWJiere more thaii two NM .^?]i?I?§ -^PO^^i^^S !^

more ciiirent-car^

gdirti^Jhermd

jbetweea cables, &e alb wable ampacity of each coaduqto^

shall be adjusted in accordmi^cewidi^ X?!?M ?l9f lKW^)i^)::

III. Construction Specifications

334.100 Construction. The outer cable sheath of
nonmetallic-sheathed cable shall be a nonmetallic material

334.104 Conductors. The 600-volt insulated conductors
shall be sizes 14 AWG through 2 AWG copper conductors
or sizes 12 AWG through 2 AWG aluminum or copper-
clad aluminum conductors. The jcommumcations;
conductors shall comply with Part V of Article 800.

334.108 Equipment Grounding iConducte^^^ In addition
to the insulated conductors, the cable shall have an
insulated, |Dpvere3j or bare b^uipment grounding conductor,

334.112 Insulation. The insulated power conductors shall be
one of the types listed in Table 310.13j;A3 that are suitable for
branch-circuit wiring or one that is identified for use in these
cables. Conductor insulation shall be rated at 90°C (194°F).

FPN: Types NM, NMC, and NMS cable identified by the
markings NM-B, NMC-B, and NMS-B meet this
requirement.

334.116 Sheath. The outer sheath of nonmetallic-sheathed
cable shall comply with 334.1 16(A), (B), and (C).

(A) Type NM. The overall covering shall be flame
retardant and moisture resistant.

(B) Type NMC. The overall covering shall be flame
retardant, moisture resistant, fiingus resistant, and corrosion
resistant.

2010 California Electrical Code

70-187

336.1

ARTICLE 336 ~ POWER AND CONTROL TRAY CABLE: TYPE TC

(C) Type NMS. The overall covering shall be flame
retardant and moisture resistant. The sheath shall be
applied so as to separate the power conductors from the
communications conductors.

ARTICLE 336

Power aiid Control Tray Cable: Type TC

I. General

336.1 Scope. This article covers the use, installation, and
construction specifications for power and control tray
cable, Type TC.

336.2 Definition.

Power and Control Tray Cable, Type TC. A factory
assembly of two or more insulated conductors, with or
without associated bare or covered grounding conductors,
under a nonmetallic jacket.

II. Installation

336.10 Uses Permitted. Type TC cable shall be permitted

to be used as follows:

(1) For power, lighting, control, and signal circuits.

(2) In cable trays.

(3) In raceways.

(4) In outdoor locations supported by a messenger wire.

(5) For Class 1 circuits as permitted in Parts II and III of
Article 725.

(6) For non-power-limited fire alarm circuits if conductors
comply with the requirements of 760.49.

(7) In industrial establishments where the conditions of
maintenance and supervision ensure that only qualified
persons service the installation, and where the cable is
continuously supported and protected against physical
damage using mechanical protection, such as struts,
angles, or channels, Type TC tray cable that complies
with the crush and impact requirements of Type MC
cable and is identified for such use with the marking
Type TC-ER shall be permitted between a cable tray
and the utilization equipment or device. The cable shall
be secured at intervals not exceeding 1.8 m (6 ft).
Equipment grounding for the utilization equipment shall
be provided by an equipment grounding conductor
within the cable. In cables containing conductors sized 6
AWG or smaller, the equipment grounding conductor
shall be provided within the cable or, at the time of
installation, one or more insulated conductors shall be
permanently identified as an equipment grounding
conductor in accordance with 250.1 19(B).

Exception: Wltere not subject to physical 0mqge, Typ^ TC-ER
shall be permitted to tramiiionibetween cable frays and between
cablS trays and vtilkation equipment gt decides for a distance
pot to exceed LS m (6 ft) without cohtinygus support. The cable
'shall be mechanically supported Where exiting the cable tray to
'ensure that the minimum bending radius is, not exceeded:

(8) Where installed in wet locations, Type TC cable shall
also be resistant to moisture and corrosive agents.

FPN: See 310.10 for temperature limitation of conductors.

336.12 Uses Not Permitted. Type TC tray cable shall not
be installed or used as follows:

(1) Installed where it will be exposed to physical damage

(2) Installed outside a raceway or cable tray system, except
as permitted in 336.10(7)

(3) Used where exposed to direct rays of the sun, unless
identified as sunlight resistant

(4) Direct buried, unless identified for such use

336.24 Bending Radius. Bends in Type TC cable shall be
made so as not to damage the cable. For Type TC cable
without metal shielding, the minimum bending radius shall
be as follows:

(1) Four times the overall diameter for cables 25 mm (1
in.) or less in diameter

(2) Five times the overall diameter for cables larger than 25
mm (1 in.) but not more than 50 mm (2 in.) in diameter

(3) Six times the overall diameter for cables larger than 50
mm (2 in.) in diameter

Type TC cables with metallic shielding shall have a
minimum bending radius of not less than 12 times the cable
overall diameter.

336.80 Ampacity. The ampacity of Type TC tray cable
shall be determined in accordance with 392. 11 for 14 AWG
and larger conductors, in accordance with 402.5 for 18
AWG through 16 AWG conductors where installed in
cable tray, and in accordance with 310.15 where installed
in a raceway or as messenger-supported wiring.

III. Construction Specifications

336.100 Construction. A metallic sheath or armor as
defined in 330.116 shall not be permitted either under or
over the nonmetallic jacket. Metallic shield(s) shall be
permitted over groups of conductors, under the outer
jacket, or both.

336.104 Conductors. The insulated conductors of Type
TC cables shall be in sizes 18 AWG to; 1000 kcmil copper,
moke], or nickel-coatedj copper j and sizes 12 AWG through
1000 kcmil aluminum or copper-clad aluminum. Insulated
conductors of sizes 14 AWG, and larger copper, nickel, or
bickel-coated copp^, and sizes 12 AWG through iOOQ

70-1 e

2010 California Electrical Code

ARTICLE 338 - SERVICE-ENTRANCE CABLE: TYPE SE AND USE

^38.12

jtciqiil aluminum or copper-clad aluminum shall be one of
the types listed in Table 310.13(A) or Table 310.1 3(B) that
is suitable for branch circuit and feeder circuits or one that
is identified for such use.

(A) Fire Alarm Systems. Where used for fire alarm
systems, conductors shall also be in accordance with 760 .p9]

(B) Thermocouple Circuits. Conductors in Type TC cable
used for thermocouple circuits in accordance with Part III
of Article 725 shall also be permitted to be any of the
materials used for thermocouple extension wire.

(C) Class 1 Circuit Conductors. Insulated conductors of
18 AWG and 16 AWG copper shall also be in accordance
with 725.49;

336.116 Jacket. The outer jacket shall be a flame-
retardant, nonmetallic material.

336.120 Marking. There shall be no voltage marking on a
Type TC cable employing thermocouple extension wire.

■ :; Sferyi|e^]B^itr^^ SE aiid;:XJSi;1:j

I. General

338.1 Scope. This article covers the use, installation, and
construction specifications of service-entrance cable.

338.2 Definitions.

Service-Entrance Cable. A single conductor or
multiconductor assembly provided with or without an
overall covering, primarily used for services, and of the
following types:

Type SE. Service-entrance cable having a flame-retardant,
moisture-resistant covering.

Type USE. Service-entrance cable, identified for
underground use, having a moisture-resistant covering, but
not required to have a flame-retardant covering.

II. Installation

338.10 Uses Permitted.

(A) Service-Entrance Conductors. Service-entrance cable
shall be permitted to be used as service-entrance
conductors and shall be installed in accordance with 230.6,
230.7, and Parts II, III, and IV of Article 230.

(B) Branch Circuits or Feeders.

(1) Grounded Conductor Insulated. Type SE service-
entrance cables shall be permitted in wiring systems where
all of the circuit conductors of the cable are of the
ihermosai or thermoplastic type.

(2) Grounded Conductor Not Insulated. Type SE

service -entrance cable shall be permitted for use where the
insulated conductors are used for circuit wiring and the
uninsulated conductor is used only for equipment
grounding purposes.

Exception: Uninsulated conductors shall be permitted as a
grounded conductor in accordance with250J2 and 250:140
'Wh&e th$ uninsulated grounded conductor of jH^^^
priginates in service equipmenty and 225.30 through 225.40.

(3) Temperature Limitations. Type SE service -entrance
cable used to supply appliances shall not be subject to
conductor temperatures in excess of the temperature
specified for the type of insulation involved.

(4) Installation Methods for Branch Circuits and
Feeders.

(a) Interior Installations. In addition to the provisions
of this article, Type SE service-entrance cable used for
interior wiring shall comply with the installation
requirements of Part II of Article 334.

FPN: See 310.10 for temperature limitation of conductors.

(b) Exterior Installations. In addition to the
provisions of this article, service-entrance cable
used for feeders or branch circuits, where installed
as exterior wiring, shall be installed in accordance
with Part I of Article 225. The cable shall be
supported in accordance with 334.30. Type USE
cable installed as underground feeder and branch
circuit cable shall comply with Part II of Article
340.

338.12 tlses;Npt Permitted^

(A) SeiTvice-Eiitrance Cable* Service-entrance cable (SEJ
^all hot ;be xised under tihe loilQwing conditims ofinthe
Ipllowinglpcations:

(1) ^WSer^ subject to physicaf damage uiileiss^^
accordance with 230.50(A)

(2) Underground with or withaiit a raceway

(3) For exterior braEi^h circiiits arid feeder wiring unless
the installation complies; with the provisions of Part I
of ^tic|e;:225 apd is; in accoriiance with
=53430; or is ;iusea as; m^^senger-supportedj^^
'^kxm^^mj!^ il :6| Ajrticfe 396

2010 California Electrical Code

70-189

338.24

ARTICLE 340 -UNDERGROUND FEEDER AND BRANCH-CIRUIT CABLE: TYPE UF

(B) Ujttdergroiittd Se^^ Cable. Underground

servjce-ealrance cable (USE) shall not be used uader the
lollowing COTditions pr 1b the jfollowmg tocatiqns:

(1) Fox intMQOKM^S

(2) For above^omdriosM

feimerges from J:hegroimd and k^t^^ an;

enciosrire at an outdoor location and the cable i$
protected in accordance with 300,5(0)!

(3) 1^ aerial cable jmless it is a .midfeondt*ctof cable

^ssenger-sn|)£^5djj wto ^in^l^accordance^^^ with
22510 anCfS^n of Arti

338.24 Bending Radius. Bends in Types USE and SE
cable shall be so made that the cable will not be damaged.
The radius of the curve of the inner edge of any bend,
during or after installation, shall not be less than five times
the diameter of the cable.

III. Construction

338.100 Construction. Cabled, single-conductor. Type USE
constructions recognized for underground use shall be
permitted to have a bare copper conductor cabled with the
assembly. Type USE single, parallel, or cabled conductor
assemblies recognized for underground use shall be permitted
to have a bare copper concentric conductor apphed. These
constructions shall not require an outer overall covering.

FPN: See 230.41, Exception, item (2), for directly buried,
uninsulated service-entrance conductors.

Type SE or USE cable containing two or more
conductors shall be permitted to have one conductor
uninsulated.

338.120 Marking. Service-entrance cable shall be marked
as required in 310.11. Cable with the neutral conductor
smaller than the ungrounded conductors shall be so marked.

; Underground Feeder and jSrattch^Circiiit

l\<--: .:. :'^:; ■i!:Cabll€: TypeUF::;::j^:-\; ';■ :'/[':,■■ j

I. General

340.1 Scope. This article covers the use, installation, and
construction specifications for underground feeder and
branch-circuit cable, Type UF.

1 340.2 Definition.

Underground Feeder and Branch- Circuit Cable, Type UF.
A factory assembly of one or more insulated conductors

with an integral or an overall covering of nonmetallic
material suitable for direct burial in the earth.

340.6 Listing Requirements. Type UF cable shall be listed.

II. Installation

340.10 Uses Permitted. Type UF cable shall be permitted

as follows:

(1) For use underground, including direct burial in the
earth. For underground requirements, see 300.5.

(2) As single-conductor cables. Where installed as single-
conductor cables, all conductors of the feeder grounded
conductor or branch circuit, including the grounded
conductor and equipment grounding conductor, if any,
shall be installed in accordance with 300.3.

(3) For wiring in wet, dry, or corrosive locations under the
recognized wiring methods of this Code.

(4) Installed as nonmetallic-sheathed cable. Where so
installed, the installation and conductor requirements
shall comply with Parts II and III of Article 334 and
shall be of the multiconductor type.

(5) For solar photovoltaic systems in accordance with 690.3 1 .

(6) As single-conductor cables as the nonheating leads for
heating cables as provided in 424.43.

(7) Supported by cable trays. Type UF cable supported by
cable trays shall be of the multiconductor type.

FPN: See 310.10 for temperature limitation of conductors.
340.12 Uses Not Permitted. Type UF cable shall not be
used as follows:

(1) As service-entrance cable

(2) In commercial garages

(3) In theaters and similar locations

(4) In motion picture studios

(5) In storage battery rooms

(6) In hoistways or on elevators or escalators

(7) In my hazardous (classified) location, eicepj; as
pftewise permitted^

(8) Embedded in poured cement, concrete, or aggregate,
except where embedded in plaster as nonheating leads
where permitted in 424.43

(9) Where exposed to direct rays of the sun, unless
identified as sunlight resistant

(10) Where subject to physical damage

(11) As overhead cable, except where installed as
messenger-supported wiring in accordance with Part
II of Article 396

340.24 Bending Radius. Bends in Type UF cable shall be
so made that the cable is not damaged. The radius of the
curve of the inner edge of any bend shall not be less than
five times the diameter of the cable.

340.80 Ampacity. The ampacity of Type UF cable shall be
that of 60°C (140^F) conductors in accordance with 310.15.

70-190

2010 California Electrical Code

ARTICLE 342 - INTERMEDIATE METAL CONDUIT: TYPE IMC

342.26

III. Construction Specifications

340.104 Conductors. The conductors shall be sizes 14
AWG copper or 12 AWG aluminum or copper-clad
aluminum through 4/0 AWG.

340.108 Equipment Grounding jConductpn In addition
to the insulated conductors, the cable shall be permitted to
have an insulated or bare equipment grounding conductor.

340.112 Insulation. The conductors of Type UF shall be one
of the moisture-resistant types listed in Table 310.13(AJ that is
suitable for branch-circuit wiring or one that is identified for
such use. Where installed as a substitute wiring method for NM
cable, the conductor insulation shall be rated 90°C (194°F).

340.116 Sheath. The overall covering shall be flame
retardant; moisture, fungus, and corrosion resistant; and
suitable for direct burial in the earth.

„.jr-' ARTICLE.342
; Ihteiljmediate Metal^ type IMC

I. General

342.1 Scope. This article covers the use, installation, and
construction specifications for intermediate metal conduit
(IMC) and associated fittings.

342.2 Definition.

Intermediate Metal Conduit (IMC). A steel threadable
raceway of circular cross section designed for the physical
protection and routing of conductors and cables and for use
as an equipment grounding conductor when installed with
its integral or associated coupling and appropriate fittings.

342.6 Listing Requirements. IMC, factory elbows and
couplings, and associated fittings shall be listed.

II. Installation
342.10 Uses Permitted.

(A) All Atmospheric Conditions and Occupancies. Use

of IMC shall be permitted under all atmospheric condidons
and occupancies.

(B) Corrosion Environments. IMC, elbows, couplings,
and fittings shall be permitted to be installed in concrete, in
direct contact with the earth, or in areas subject to severe
corrosive influences where protected by corrosion
protection and judged suitable for the condition.

(C) Cinder Fill. IMC shall be permitted to be installed in or
under cinder fill where subject to permanent moisture where
protected on all sides by a layer of noncinder concrete not
less than 50 mm (2 in.) thick; where the conduit is not less
than 450 mm (18 in.) under the fill; or where protected by
corrosion protection and judged suitable for the condition.

(D) Wet Locations. All supports, bolts, straps, screws, and
so forth, shall be of corrosion-resistant materials or
protected against corrosion by corrosion-resistant materials.

FPN: See 300.6 for protection against corrosion.

342.14 Dissimilar Metals, Where practicable, dissimilar
metals in contact anywhere in the system shall be avoided
to eliminate the possibility of galvanic action.

Aluminum fittings and enclosures shall be permitted to
be used with IMC.

342.20 Size.

(A) Minimum. IMC smaller than metric designator 16
(trade size Vi) shall not be used.

(B) Maximum. IMC larger than metric designator 103
(trade size 4) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

342.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

Cables shall be permitted to be installed where such use is
not prohibited by the respective cable articles. The number
of cables shall not exceed the allowable percentage fill
specified in Table I, Chapter 9.

342.24 Bends — How Made. Bends of IMC shall be so
made that the conduit will not be damaged and the internal
diameter of the conduit will not be effectively reduced. The
radius of the curve of any field bend to the centerline of the
conduit shall not be less than indicated in Table 2, Chapter 9.

342.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

2010 California Electrical Code

70-191

342,28

ARTICLE 344 -RIGID METAL CONDUIT: TYPE RMC

342.28 Reaming and Threading. All cut ends shall be
reamed or otherwise finished to remove rough edges. Where
conduit is threaded in the field, a standard cutting die with a
taper of 1 in 16 (Va in. taper per foot) shall be used.

FPN: See ANSI/ASME B.1.20.1-1983, Standard for Pipe
Threads, General Purpose (Inch).

342.30 Securing and Supporting. IMC shall be installed
as a complete system in accordance with 300.18 and shall
be securely fastened in place and supported in accordance
with 342.30(A) and (B), or pennitted to be xmsupported iri
accordance with 34230(C).

(A) Securely Fastened. Each IMC shall be securely
fastened within 900 mm (3 ft) of each outlet box, junction
box, device box, cabinet, conduit body, or other conduit
termination. Fastening shall be permitted to be increased to
a distance of 1.5 m (5 ft) where structural members do not
readily permit fastening within 900 mm (3 ft). Where
approved, conduit shall not be required to be securely
fastened within 900 mm (3 ft) of the service head for
above-the-roof termination of a mast.

(B) Supports. IMC shall be supported in accordance with
one of the following:

(1) Conduit shall be supported at intervals not exceeding 3
m(lOft).

(2) The distance between supports for straight runs of
conduit shall be permitted in accordance with Table
344.30(B)(2), provided the conduit is made up with
threaded couplings and such supports prevent
transmission of stresses to termination where conduit
is deflected between supports.

(3) Exposed vertical risers from industrial machinery or
fixed equipment shall be permitted to be supported at
intervals not exceeding 6 m (20 ft) if the conduit is
made up with threaded couplings, the conduit is
supported and securely fastened at the top and bottom
of the riser, arid no other means of intermediate
support is readily available.

(4) Horizontal runs of IMC supported by openings through
fi-aming members at intervals not exceeding 3 m (10 ft)
and securely fastened within 900 mm (3 ft) of
termination points shall be permitted.

(C) ^tlnsugported - Rac^^^ ^ pyer^ized, 'conceiitrid
pr eccentric knockouts are not encountered^ Type, IMC)
shall be permitted to be unsupported where the raceway i^
not more than 450 mm (18 in.) ajQd remains in unbroken
lengths (without coupling); Such raceways shall terminate
in an outlet box, junction box, device box, cabinet, or oti^i:
termination at each end of tiie raceway.

342.42 Couplings and Connectors.

(A) Threadless. Threadless couplings and connectors used
with conduit shall be made tight. Where buried in masonry
or concrete, they shall be the concretetight type. Where
installed in wet locations, they shall comply with 314.15.
Threadless couplings and connectors shall not be used on
threaded conduit ends unless listed for the purpose.

(B) Running Threads. Running threads shall not be used
on conduit for connection at couplings.

342.46 Bushings. Where a conduit enters a box, fitting, or
other enclosure, a bushing shall be provided to protect the
wire from abrasion unless the design of the box, fitting, or
enclosure is such as to afford equivalent protection.

FPN: See 300.4(G) for the protection of conductors 4 AWG
and larger at bushings.

342.56 Splices and Taps. Splices and taps shall be made
in accordance with 300.15.

342.60 Grounding. IMC shall be permitted as an
equipment grounding conductor.

III. Construction Specifications

342.120 Marking. Each length shall be clearly and
durably marked at least every 1.5 m (5 ft) with the letters
IMC. Each length shall be marked as required in 1 10.21.

342.130 Standard Lengths. The standard length of IMC
shall be 3.05 m (10 ft), including an attached coupHng, and
each end shall be threaded. Longer or shorter lengths with
or without coupling and threaded or unthreaded shall be
permitted.

AI^TIGLE344
iUgidMetyi Conduits RMC

I. General

344.1 Scope. This article covers the use, installation, and
construction specifications for rigid metal conduit (RMC)
and associated fittings.

344.2 Definition.

Rigid Metal Conduit (RMC). A threadable raceway of
circular cross section designed for the physical protection
and routing of conductors and cables and for use as an
equipment grounding conductor when installed with its
integral or associated coupling and appropriate fittings.
RMC is generally made of steel (ferrous) with protective
coatings or aluminum (nonferrous). Special use types are
red brass and stainless steel.

•

70-192

2010 California Electrical Code

ARTICLE 344 - RIGID METAL CONDUIT: TYPE RMC

344.30

344.6 Listing Requirements. RMC, factory elbows and
couplings, and associated fittings shall be listed.

II. Installation

344.10 Uses Permitted.

(A) Atmospheric Conditions and Occupancies.

j^i) Galvaiifeed $^^ St^l RMC Galvan^

st^el and : stainless steej RMC shall be permitted tinder all
atmospheric conditions and occupancies.

{2} Red 6rass SMC Kedbrass RMC shall beperrrritted to be
installed for direct btirial and swimming pool application^;;

i(3)'j;Jj^^ RMC.^i^ RMC shaUjbe |}en^^

h^^m^^^i .^here judg^;suiy^^^

aitMnurn! condiiit enea^Sd in concrete or in direct contact with
\M eaSh I shall he prnvidift. . ^^i approved si5)piementary
coitosion protecSon.

(4) Ferrijus Raceways and |1ttiiigs. Ferrous raceways and
fittings protected from corrosion solely by enamel shall be
permitted only indoors and in occupancies not subject to severe
corrosive influences.

(BJ Cp>rrtf^^ Environments.

(ij > Galvkirized StersfaiiUe^ISteel^ and Red Bms 'ftMgi
Elbows, fcottpffiagi^ and FiMng$. Galvani^ steely stainksd
steel, andired bra^s RMC elbows, couplings, and fittings shall
be permitted to be installed in concrete, in direct contact with
the earth, or in areas subject to severe corrosive influences
where protected by corrosion protection and judged suitable for
the condition.

j(2X_Supplementaix„.F^ I'pt AluiMnyumj;!^

Ifiuminum RMjC Jshall provided with approved

suppiementaiy corrosion 'proifeclion where encased in concrete
or in direct coo^t with the e^:

brass RMC shall be permitted to be installed in or under
cinder fill where subject to permanent moisture where
protected on all sides by a layer of noncinder concrete not
less than 50 mm (2 in.) thick; where the conduit is not less
than 450 mm (18 in.) under the fill; or where protected by
corrosion protection and judged suitable for the condition.

(D) Wet Locations. All supports, bolts, straps, screws, and
so forth, shall be of corrosion-resistant materials or
protected against corrosion by corrosion-resistant materials.

FPN: See 300.6 for protection against corrosion.

344.14 Dissimilar Metals. Where practicable, dissimilar
metals in contact anywhere in the system shall be avoided
to ehminate the possibility of galvanic action. Aluminum
fittings and enclosures shall be permitted to be used with
steel RMC, and steel fittings and enclosures shall be
permitted to be used with aluminum RMC where not
subject to severe corrosive influences.

344.20 Size.

(A) Minimum. RMC smaller than metric designator 16
(trade size Yi) shall not be used.

Exception: For enclosing the leads of motors as permitted
in 430.245(B).

(B) Maximum. RMC larger than metric designator 155
(trade size 6) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

344.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

344.24 Bends — How Made. Bends of RMC shall be so
made that the conduit will not be damaged and so that the
internal diameter of the conduit will not be effectively
reduced. The radius of the curve of any field bend to the
centerline of the conduit shall not be less than indicated in
Table 2, Chapter 9.

344.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

344.28 Reaming and Threading. All cut ends shall be
reamed or otherwise finished to remove rough edges.
Where conduit is threaded in the field, a standard cutting
die with a 1 in 16 taper (%-in. taper per foot) shall be used.

FPN: See ANSI/ASME B. 1.20. 1-1983, Standard for Pipe
Threads, General Purpose (Inch).

344.30 Securing and Supporting. RMC shall be installed
as a complete system in accordance with 300.18 and shall
be securely fastened in place and supported in accordance
with 344.30(A) and (B) jor permitted; to be unsupported iri
jaccordancewfth 34430(C).

2010 California Electrical Code

70-193

344.42

ARTICLE 348 -FLEXIBLE METAL CONDUIT; TYPE FMC

(A) Securely Fastened. RMC shall be securely fastened
within 900 mm (3 ft) of each outlet box, junction box,
device box, cabinet, conduit body, or other conduit
termination. Fastening shall be permitted to be increased to
a distance of 1 .5 m (5 ft) where structural members do not
readily permit fastening within 900 mm (3 ft). Where
approved, conduit shall not be required to be securely
fastened within 900 mm (3 ft) of the service head for
above-the-roof termination of a mast.

(B) Supports. RMC shall be supported in accordance with
one of the following:

(1) Conduit shall be supported at intervals not exceeding 3
m(lOft).

(3) Exposed vertical risers from industrial machinery or
fixed equipment shall be permitted to be supported at
intervals not exceeding 6 m (20 ft) if the conduit is
made up with threaded coupHngs, the conduit is
supported and securely fastened at the top and bottom
of the riser, and no other means of intermediate
support is readily available.

(4) Horizontal runs of RMC supported by openings
through framing members at intervals not exceeding 3
m (10 ft) and securely fastened within 900 mm (3 ft) of
termination points shall be permitted.

Table 344.30(B)(2) Supports for Rigid Metal Conduit

Maximum Distance

Between Rigid Metal

Conduit Size

Conduit Supports

Metric

Designator

Trade Size

m ft

16-21

Vi-V.

3.0 10

3.7 12

35-^1

VA-VA

4.3 14

53-63

l-VA

4.9 16

78 and larger

3 and larger

6.1 20

^i(Cy;'UrtSttpparte^ ::ilaceway.s* Whete. dyersizei. boilcenfie
jor eccentric knockputsj atre: pot; bncouiit^ed^ 1)^^ = W:^^
sMl b0 ^permitted: to be uii^u|^fted^ where tK^; rac^^v^ is^
tot rtiore than 450 mrri 0i;8 ii^i)Jaixd:. remains iniinibrbkiri
lengths' (without coupling); 'Sucliracewa3fr^ shall ^temiiiiate
in an outlet box^ junction boxVdevic^box^c^
terminaticm at each cMjbf the.^tabev^

344.42 Couplings and Connectors.

(B) Running Threads. Running threads shall not be used
on conduit for connection at couplings.

344.46 Bushings. Where a conduit enters a box, fitting, or
other enclosure, a bushing shall be provided to protect the
wire from abrasion unless the design of the box, fitting, or
enclosure is such as to afford equivalent protection.

FPN: See 300.4(G) for the protection of conductors sizes 4
AWG and larger at bushings.

344.56 Splices and Taps. SpUces and taps shall be made
in accordance with 300.15.

344.60 Grounding. RMC shall be permitted as an
equipment grounding conductor.

III. Construction Specifications

344.120 Marking. Each length shall be clearly and
durably identified in every 3 m (10 ft) as required in the
first sentence of 110.21. Nonferrous conduit of corrosion-
resistant material shall have suitable markings.

344.130 Standard Lengths. The standard length of RMC
shall be 3.05 m (10 ft), including an attached coupling, and
each end shall be threaded. Longer or shorter lengths with
or without coupling and threaded or unthreaded shall be
permitted.

:;:.;r;:ARTICLE 34R ^-
Flexible Metk Conduit: l^pfeFlNiC

I. General

348.1 Scope. This article covers the use, installation, and
construction specifications for flexible metal conduit
(FMC) and associated fittings.

348.2 Definition.

Flexible Metal Conduit (FMC). A raceway of circular cross
section made of helically wound, formed, interlocked metal
strip.

70-194

2010 California Electrical Code

ARTICLE 348 - FLEXIBLE METAL CONDUIT: TYPE FMC

348.30

348.6 Listing Requirements. FMC and associated fittings
shall be listed.

II. Installation

348.10 Uses Permitted. FMC shall be permitted to be
used in exposed and concealed locations.

348.12 Uses Not Permitted. FMC shall not be used in the
following:

(1) Igv^etfoc^tio'B^

(2) In hoistways, other than as permitted in 620.21(A)(1)

(3) In storage battery rooms

(4) In any hazardous (classified) location except asi

permitted % other articles m^^^^

(5) Where exposed to materials having a deteriorating

effect on the installed conductors, such as oil or
gasohne

(6) Underground or embedded in poured concrete or

aggregate

(7) Where subject to physical damage

348.20 Size.

(A) Minimum. FMC less than metric designator 16 (trade
size Yi) shall not be used unless permitted in 348.20(A)(1)
through (A)(5) for metric designator 12 (trade size 3/8).

(1) For enclosing the leads of motors as permitted in
430.245(B)

(2) In lengths not in excess of 1.8 m (6 ft) for any of the
following uses:

a. For utilization equipment

b. Aspart of a listed assembly

c. For tap connections to luminaires as permitted in

410.;n7(C)

(3) For manufactured wiring systems as permitted in
604.6(A)

(4) In hoistways as permitted in 620.21(A)(1)

(5) As part of a listed assembly to connect wired luminaire
sections as permitted in 410.[|||(C)

Table 348.22 Maximum Number of Insulated Conductors in Metric

(B) Maximum. FMC larger than metric designator 103
(trade size 4) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

348.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9, or as
permitted in Table 348.22, or for metric designator 12
(trade size 3/8).

Cables shall be permitted to be installed where such
use is not prohibited by the respective cable articles. The
number of cables shall not exceed the allowable percentage
fill specified in Table 1, Chapter 9.

348.24 Bends — How Made. Bends in conduit shall be made
so that the conduit is not damaged and the intemal diameter of
the conduit is not effectively reduced. Bends shall be permitted
to be made manually without auxiliary equipment. The radius of
the curve to the centerline of any bend shall not be less than
shown in Table 2, Chapter 9 using the column "Other Bends."

348.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

348.28 Trimming. All cut ends shall be trimmed or
otherwise finished to remove rough edges, except where
fittings that thread into the convolutions are used.

348.30 Securing and Supporting. FMC shall be securely
fastened in place and supported in accordance with
348.30(A) and (B).

(A) Securely Fastened. FMC shall be securely fastened in
place by an approved means within 300 mm (12 in.) of
each box, cabinet, conduit body, or other conduit
termination and shall be supported and secured at intervals
not to exceed 1.4 m (4!/2 ft).

Designator 12 (Trade Size 3/8) Flexible Metal Conduit*

Types RFH-2, SF-2

Types TF,

XHHW, TW

Types TFN, THHN, THWN

Types FEP, FEBP, PF, PGF

Size
(AWG)

Fittings

Inside

Conduit

Fittings
Outside
Conduit

Fittings

Inside

Conduit

Fittings
Outside
Conduit

Fittings

Inside

Conduit

Fittings
Outside
Conduit

Fittings

Inside

Conduit

Fittings
Outside
Conduit

—

*In addition, one jtisiilated,- covered or bare equipment grounding conductor of the same size shall be permitted.

2010 California Electrical Code

70-195

348.42

ARTICLE 350 -LIQUIDTIGHT FLEXIBLE METAL CONDUIT: TYPE LFMC

Exception No. I: Where FMC is fished bep^een access,
points through concealed spaces, m buildings 6t

sttuctures arid supporting is impractical.

Exception No. 2: Where flexibility is necessary after
imtaUation, lengths shall not exceed the following:

(1) 900 mm (3 ft) for metric designators 16 through 35
(trade sizes V2 through I V4)

(2) 1200 mm (4 ft) for metric designators 41 through
53 (trade sizes IV2 through 2)

(3) 1500 mm (5 ft) for metric designators 63 (trade
size 2V2) and larger

Exception No. 3: Lengths not exceeding 1.8 m (6 ft) from a

luminaire terminal connection for tap connections to

luminaires as permitted in 410.JI?:(C).

Exception No. 4: Lengths not exceeding 1.8 m (6 ft) from

the last point where the raceway is securely fastened for

connections within an accessible ceiling to luminaire(s) or

other equipment.

(B) Supports. Horizontal runs of FMC supported by

openings through framing members at intervals not greater

than 1.4 m (4/4 fl) and securely fastened within 300 mm

(12 in.) of termination points shall be permitted.

348.42 Couplings and Connectors. Angle connectors

shall not be used for concealed raceway installations.

348.56 Splices and Taps. Splices and taps shall be made

in accordance with 300.15.

348.60 Grounding and Bonding. Where used to connect

equipment where flexibility is required ;afl;er instaliation, an

equipment grounding conductor shall be installed.

Where flexibility is not required after mstaltation,
FMC shall be permitted to be used as an equipment
grounding conductor when installed in accordance with
250.118(5).

Where required or installed, equipment grounding
conductors shall be installed in accordance with
250.134(B).

Where required or installed, equipment bonding
jumpers shall be installed in accordance with 250.102.

■ ^ ARTICLE'350 /

Liquidtight Flerible Metal Conduit: Type

'■■■ LFMC-':";;\

I. General

350.1 Scope. This article covers the use, installation, and
construction specifications for liquidtight flexible metal
conduit (LFMC) and associated fittings.

350.2 Definition.

Liquidtight Flexible Metal Conduit (LFMC). A raceway
of circular cross section having an outer liquidtight,
nonmetallic, sunlight-resistant jacket over an inner flexible
metal core with associated couplings, connectors, and
fittings for the installation of electric conductors.

350.6 Listing Requirements. LFMC and associated
fittings shall be listed.

II. Installation

350.10 Uses Permitted. LFMC shall be permitted to be

used in exposed or concealed locations as follows:

(1) Where conditions of installation, operation, or
maintenance require flexibility or protection from
liquids, vapors, or solids

(2) As permitted by 501.10(B), 502.10, 503.10, and 504.20
and in other hazardous (classified) locations where
specifically approved, and by 553.7(B)

(3) For direct burial where listed and marked for the
purpose

350.12 Uses Not Permitted. LFMC shall not be used as
follows:

(1) Where subject to physical damage

(2) Where any combination of ambient and conductor
temperature produces an operating temperature in
excess of that for which the material is approved

350.20 Size.

(A) Minimum. LFMC smaller than metric designator 16
(trade size Vi) shall not be used.

Exception: LFMC of metric designator 12 (trade size 3/8)
shall be permitted as covered in 348.20(A).

(B) Maximum. The maximum size of LFMC shall be
metric designator 103 (trade size 4).

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

350.22 Number of Conductors or Cables.

(A) Metric Designators 16 through 103 (Trade Sizes Vi
through 4). The number of conductors shall not exceed that
permitted by the percentage fill specified in Table 1 , Chapter 9.

70-196

2010 Califomia Electrical Code

ARTICLE 352 - RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC

352.10

(B) Metric Designator 12 (Trade Size 3/8). The number
of conductors shall not exceed that permitted in Table
348.22, "Fittings Outside Conduit" columns.

350.24 Bends — How Made. Bends in conduit shall be so
made that the conduit will not be damaged and the internal
diameter of the conduit will not be effectively reduced.
Bends shall be permitted to be made manually without
auxiliary equipment. The radius of the curve to the
centerline of any bend shall not be less than required in
Table 2, Chapter 9 using the column "Other Bends."

350.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

350.30 Securing and Supporting. LFMC shall be
securely fastened in place and supported in accordance
with 350.30(A) and (B).

(A) Securely Fastened. LFMC shall be securely fastened
in place by an approved means within 300 mm (12 in.) of
each box, cabinet, conduit body, or other conduit
termination and shall be supported and secured at intervals
not to exceed 1.4 m (AVi ft).

Exception No. 1: Where LFMC is fished between access
points thfpugh concealed spaces in finished buildings or
stnicture^and supporting is imprgcticql

Exception No, 2: Where flexlbiHty is jiecessary after
installatiSn, lengths shall not excmd the fal^^

(1) 9Q0 mm (3 ft) for metric designators ,1 6 through SS

(trade sizes ¥2 through ^ / §|

'63ftrgde}izesJJ£thr^^^

(3) \l5d0 mm Q ft) for metric designators 63 (trade^

'size Ifij: dnd^ Idf^^K

Exception No. 3: Lengths not exceeding L8 m (6 ft) from a
luminaire terminal connection for tap conductors to
luminaires, as permitted in 410Ai{^C).

Exception No. 4: Lengths not exceeding L8 m (6 ft) from
the last point where the raceway is securely fastened for
connections within an accessible ceiling to luminaire(s) or
other equipment.

(B) Supports. Horizontal runs of LFMC supported by
openings through framing members at intervals not greater
than 1.4 m {AVi ft) and securely fastened within 300 mm
(12 in.) of termination points shall be permitted.

350.42 Couplings and Connectors. Angle connectors
shall not be used for concealed raceway installations.

350.56 Splices and Taps. Splices and taps shall be made
in accordance with 300.15.

350.60 Grounding and Bonding. Where used to connect
equipment where flexibility is required iafter;iipistkliat^ an
equipment grounding conductor shall be installed.

Where flexibility is not required after jinstajto
LFMC shall be permitted to be used as an equipment
grounding conductor when installed in accordance with
250.118(6).

Where required or installed, equipment grounding
conductors shall be installed in accordance with
250.134(B).

Where required or installed, equipment bonding
jumpers shall be installed in accordance with 250.102.

FPN: See 501.30(B), 502.30(B), 503.30(B), 505.25(B)J;,and
506J25(B) for types of equipment grounding conductors.

III. Construction Specifications

350.120 Marking. LFMC shall be marked according to
110.21. The trade size and other information required by
the listing shall also be marked on the conduit. Conduit
suitable for direct burial shall be so marked.

ARTICLE 352

Rigid Polyvinyl Chloride Conduit: tj^^^

I. General

352.1 Scope. This article covers the use, installation, and
construction specifications for rigid pQiyyinyi chloride
conduit (PyC) and associated fittings.

FFN; Refer to Article 353 for j&igh Density Polyethylene
CoTi&itt: Type HDPEj and Article 355 for Reinforced
Thermosetting Resin Conduit: Type RTRC j

352.2 Definition.

Rigid jPolyvinyl , Chloride' Conduit i(PyC);.; A rigiS
nonmetallic condiujt (RNC) of circular cross section, with
integral or associated couplings, connectors, and fittings for
the installation of electrical conductors and cables.

352.6 Listing Requirements. PVC conduit, factory
elbows, and associated fittings shall be listed.

II. Installation

352.10 Uses Permitted. The use of PVC'^O^Mt shall be
permitted in accordance with 352.10(A) through (H).

2010 California Electrical Code

70-197

352.12

ARTICLE 352 -RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC

A
C
A
C

FPN: Extreme cold may cause some nonmetallic conduits to
become brittle and, therefore, more susceptible to damage
from physical contact.

(A) Concealed. FVC c^^S^ shall be permitted in walls,
floors, and ceilings. __

(B) Corrosive Influences. Pyc!poii(juil shall be permitted
in locations subject to severe corrosive influences as
covered in 300.6 and where subject to chemicals for which
the materials are spe cifically approved.

(D) Wet Locations. PVC^lcpTKlmt shall be permitted in
portions of dairies, laundries, canneries, or other wet
locations, and in locations where walls are frequently
washed, the entire conduit system, including boxes and
fittings used therewith, shall be installed and equipped so
as to prevent water from entering the conduit. All supports,
bolts, straps, screws, and so forth, shall be of corrosion-
resistant materials or be protected against corrosion by
approved corrosion-resistant materials.

(E) Dry and Damp Locations. I^CJgcpi&ii shall be
permitted for use in dry and damp locations not prohibited
by 352.12.

(F) Exposed. PVC conduil shall be permitted for exposed
work. PVC conduit used exposed iti aieas; of physidat
damage shall be identified for theusei

'fPN:J>VC' Conduit,: Tyi0^.S€^^:m,]-^:''id^^

atea%6tp.^y&i<?^ d|t.mageJ
(G)Underground Installations. For underground
installations,^ fo and. n6fiKomogerious'PVC;^hali

i>e permitted for; difect^b aild undetgrouiid eticased in
boiictetej See 300.5 and 300.50!

(H) Support of Conduit Bodies. PVG conduit shall be
permitted to support nonmetallic conduit bodies not larger
than the largest trade size of an entering raceway. These
conduit bodies shall not support luminaires or other
equipment and shall not contain devices other than splicing
devices as permitted by 110.14(B) and 314.16(C)(2).
352.12 Uses Not Permitted. RNC shall not be used under the
following conditions.

[OSHPD I 2, 3 & 4] PVC conduit shall not be used under the
conditions specified in 352.12 (A) through (F)

(A) Hazardous (Classified) Locations. In any hazardous
(classified) location, except as permitted bj^tithe^jgrt^

(B) Support of Luminaires. For the support of luminaires
or other equipment not described in 352.10(H).

(D) Ambient Temperatures, Where subject to ambient
temperatures in excess of 50°C (122^F) unless listed
otherwise.

(E) Insulation Temperature Limitations. For conductors

or cables operating at a temperature higher than the PVC
conduit listed operating temperature rating.

Exception: Conductors or cables rated at a temperature
higher than the 'PVC^con^uii^ listed temperature rating
shall be permitted to be installed in ^^&4p^^^M^ provided
they are not operated at a temperature higher than the
¥Y^j^P^4'^ii listed temperature rating.

(F) Theaters and Similar Locations. In theaters and
similar locations, except as provided in 518.4 and 520.5.

352.20 Size.

(A) Minimum. IPVp condiiii smaller than metric
designator 16 (trade size Vi) shall not be used.

(B) Maximum. fNC cpk&M larger than metric designator
155 (trade size 6) shall not be used.

FPN: The trade sizes and metric designators are for
identification purposes only and do not relate to actual
dimensions. See 300.1(C).

352.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

352.24 Bends — How Made. Bends shall be so made that
the conduit will not be damaged and the internal diameter
of the conduit will not be effectively reduced. Field bends
shall be made only with bending equipment identified for
the purpose. The radius of the curve to the centerline of such
bends shall not be less than shown in Table 2, Chapter 9.

352.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

352.28 Trimming. All cut ends shall be trimmed inside
and outside to remove rough edges.

352.30 Securing and Supporting. PVG^condu^ shall be
installed as a complete system as provided in 300.18 and
shall be fastened so that movement from thermal expansion
or contraction is permitted. iKjOiS^^sl ^^^^^ be securely
fastened and supported in accordance with 352.30(A) and
(B) lor ^pei™fed--tb^':;|ejj^

70-198

2010 California Electrical Code

ARTICLE 352 - RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC

352,56

(A) Securely Fastened. PTGJcoMmt shall be securely
fastened within 900 mm (3 ft) of each outlet box, junction
box, device box, conduit body, or other conduit
termination. Conduit listed for securing at other than 900
mm (3 ft) shall be permitted to be installed in accordance
with the listing.

(B) Supports. PVC comiuit shall be supported as required
in iTaBlel 35230. Conduit listed for support at spacings
other than as shown in Tabl^:352 J^^ shall be permitted to
be installed in accordance with the listing. Horizontal runs
^f WiSj&lMM supported by openings through framing
members at intervals not exceeding those in Table 352.30
and securely fastened within 900 mm (3 ft) of termination
points shall be permitted.

Table 352.30 Support of Rigid Polyvinyl Chloride Conduit (PVC)

Maximum Spacing

Between

Conduit Size

Supports

Metric

Designator

Trade Size

mm or m

16-27

Vi-l

900 mm

35-53

l%-2

1.5 m

63-78

2^/2-3

1.8 m

91-129

31/2-5

2.1m

155

2.5 m

]?^:J!9§^fi^S!.fe?pfews^^are^ not enc6tin&e4^J-FVC

not mo^e Ijim and remattis in unbroken

lengths (wtHoTJl; coupiia^^^ Sii^h raceway sh^il fcOTinate in
an outlet bqxj. junction box^ device box^; cabinet, or. ^^^^^
termination at each end of th^

352.44 Expansion Fittings. Expansion fittings for PVC
conduit shall be provided to compensate for thermal expansion
and contraction where the length change, in accordance with
Table! 3 §2:44] is expected to be 6 mm (% in.) or greater in a
straight run between securely mounted items such as boxes,
cabinets, elbows, or other conduit terminations.

352.46 Bushings. Where a conduit enters a box, fitting, or
other enclosure, a bushing or adapter shall be provided to
protect the wire from abrasion unless the box, fitting, or
enclosure design provides equivalent protection.

FPN: See 300.4(G) for the protection of conductors 4 AWG
and larger at bushings.

352.48 Joints. All joints between lengths of conduit, and
between conduit and couplings, fittings, and boxes, shall be
made by an approved method.

352.56 Splices and Taps. Splices and taps shall be made
in accordance with 300.15.

Table 352.44 Expansion Characteristics of PVC Rigid Nonmetallic Conduit Coefficient of Thermal Expansion
mm/mm/°C (3.38 x l0-5 in./in./°F)

6.084 X 10-5

Temperature

Length

Temperature

Length

Temperature

Length Change of PVC Conduit

Change

Change of

Change

Change of

Change

(in./100 ft)

(°C)

PVC Conduit
(mm/m)

(-F)

PVC Conduit
(in./100 ft)

(°F)

0.30

0.20

105

4.26

0.61

0.41

110

4.46

0.91

0.61

115

4.66

1.22

0.81

120

4.87

1.52

1.01

125

5.07

1.83

1.22

130

5.27

2.13

1.42

135

5.48

2.43

1.62

140

5.68

2.74

1.83

145

5.88

3.04

2.03

150

6.08

3.35

2.23

155

6.29

3.65

2.43

160

6.49

3.95

2.64

165

6.69

4.26

2.84

170

6.90

4.56

3.04

175

7.10

4.87

3.24

180

7.30

5.17

3.45

185

7.50

5.48

3.65

190

7.71

5.78

3.85

195

7.91

100

6.08

100

4.06

200

8.11

2010 California Electrical Code

70-199

352.60

ARTICLE 353 -HIGH DENSITY POLYETHYLENE CONDUIT: TYPE HDPE CONDUIT

352.60 Grounding. Where equipment grounding is
required, a separate equipment grounding conductor shall
be installed in the conduit.

Exception No. I: As permitted in 250.134(B), Exception
No. 2, for dc circuits and 250.134(B), Exception No. 1, for
separately run equipment grounding conductors.
Exception No. 2: Where the grounded conductor is used to
ground equipment as permitted in 250.142.

III. Construction Specifications

352,lOCLConstructi0B. ^FVC conduit shall be imde of
ngid Jnonplasticized) polyvinyl ch lo ride (PVC). PVC
bonduit and fittings shall be composed of suitable
nonmetallic material that is resistant to moisture and
chemical atmospheres. For use aboveground, it shall also
be flame retardant, resistant to impact and crushing,
resistant to distortion from heat under conditions likely to
be encountered in service, and resistant to low temperature
and sunlight effects. For use underground, the material
shall be acceptably resistant to moisture and corrosive
agents and shall be of sufficient strength to withstand
abuse, such as by impact and crushing, in handling and
during installation. Where intended for direct burial,
without encasement in concrete, the material shall also be
capable of withstanding continued loading that is likely to
be encountered after installation.

352.120 Marking. Each length of i>VC oonduit shall be
clearly and durably marked at least every 3 m (10 ft) as
required in the first sentence of 110.21. The type of
material shall also be included in the marking unless it is
visually identifiable. For conduit recognized for use
aboveground, these markings shall be permanent. For
conduit limited to underground use only, these markings
shall be sufficiently durable to remain legible until the
material is installed. Conduit shall be permitted to be
surface marked to indicate special characteristics of the
material.

FPN: Examples of these markings include but are not
limited to "limited smoke" and "sunlight resistant."

■■;:;. ;;;::'';\'-' ARTICLE 3^^^^^^

Higli Density Polyethylene Conduit: Type

I. General

353.1 Scope. This article covers the use, installation, and
construction specifications for high density polyethylene
(HDPE) conduit and associated fittings.

'Gpnim£^\Jf^ /or ,:Reinforced

llhermgsettjigR^^ TyM^^fefRCl

353.2 Definition. A nonmetallic raceway of circular cross
section, with associated couplings, connectors, and fittings
for the installation of electrical conductors.

HDPE conduit and

353.6 Listing Requirements.

associated fittings shall be listed.

II. Installation

353.10 Uses Permitted. The use of HDPE conduit shall be
permitted under the following conditions:

(1) In discrete lengths or in continuous lengths from a reel

(2) In locations subject to severe corrosive influences
as covered in 300.6 and where subject to chemicals for
which the conduit is listed

(3) In cinder fill

(4) In direct burial installations in earth or concrete

FPN to (4): Refer to 300.5 and 300.50 for
underground installations.

(5) Kfeoye kbund, except as prohibited in 353.12, wherg
encasedTn. not less than 50 mm (2 in,) of concr§eJ

353.12 Uses Not Permitted. HDPE conduit shall not be
used under the following conditions:

(1) Where exposed

(2) Within a building

(3) In any hazardous (classified) location, except as
permitted bjnother articles in this Codi

(4) Where subject to ambient temperatures in excess of
50°C (122°F) unless listed otherwise

(5) For conductors or cables operating at a temperature higher
than the HDPE conduit listed operating temperature rating

Exception: Conductors or cables rated at a temperature
higher than the HDPE conduit listed temperature rating
shall he permitted to be installed in HDPE conduit,
provided they are not operated at a temperature higher
than the HDPE conduit listed temperature rating.

353.20 Size.

(A) Minimum. HDPE conduit smaller than metric
designator 16 (trade size Vi) shall not be used.

(B) Maximum. HDPE conduit larger than

designator ;155 {£ade si|e 6J shall not be used.

metric

70-200

2010 California Electrical Code

ARTICLE 354 - NONMETALLIC UNDERGROUND CONDUIT WITH CONDUCTORS: TYPE NUCC

354.10

FPN: The trade sizes and metric designators are for
identification purposes only and do not relate to actual
dimensions. See 300.1(C).

353.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

Cables shall be permitted to be installed where such
use is not prohibited by the respective cable articles. The
number of cables shall not exceed the allowable percentage
fill specified in Table 1, Chapter 9.

353.24 Bends — How Made. Bends shall be so made that
the conduit will not be damaged and the internal diameter
of the conduit will not be effectively reduced. Bends shall
be permitted to be made manually without auxiliary
equipment, and the radius of the curve to the centerline of
such bends shall not be less than shown in Table 354.24.

353.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

353.28 Trimming. All cut ends shall be trimmed inside
and outside to remove rough edges.

353.46 Bushings. Where a conduit enters a box, fitting, or
other enclosure, a bushing or adapter shall be provided to
protect the wire from abrasion unless the box, fitting, or
enclosure design provides equivalent protection.

FPN: See 300.4(G) for the protection of conductors 4 AWG
and larger at bushings.

353.48 Joints. All joints between lengths of conduit, and
between conduit and couplings, fittings, and boxes, shall be
made by an approved method.

FFN: HpPfe conduit mii be joiii^^ usmg^ eitih^^
bfectSSfijjsion, or mechanical 4iipBsj

353.56 Splices and Taps. SpHces and taps shall be made
in accordance with 300.15.

353.60 Grounding. Where equipment grounding is
required, a separate equipment grounding conductor shall
be installed in the conduit.

Exception No. 1: The equipment grounding conductor shall be
permitted to he run separately from the conduit where used for
grounding dc circuits as permitted in 2 50 J 34, Exception No. 2.

Exception No. 2: The equipment grounding conductor
shall not be required where the grounded conductor is used
to ground equipment as permitted in 250.142.

III. Construction Specifications

353.100 Construction. HDPE conduit shall be composed
of high density polyethylene that is resistant to moisture
and chemical atmospheres. The material shall be resistant
to moisture and corrosive agents and shall be of sufficient
strength to withstand abuse, such as by impact and
crushing, in handling and during installation. Where
intended for direct burial, without encasement in concrete,
the material shall also be capable of withstanding continued
loading that is likely to be encountered after installation.

353.120 Marking. Each length of HDPE shall be clearly and
durably marked at least every 3 m (10 ft) as required in 1 10.21.
The type of material shall also be included in the marking.

J ; Nonm^taliic Utiderground Coiidwit w ]

I. General

354.1 Scope. This article covers the use, installation, and
construction specifications for nonmetaUic underground
conduit with conductors (NUCC).

354.2 Definition.

NonmetaUic Underground Conduit with Conductors
(NUCC). A factory assembly of conductors or cables inside
a nonmetaUic, smooth wall conduit with a circular cross
section.

354.6 Listing Requirements.

fittings shall be listed.

NUCC and associated

II. Installation

354.10 Uses Permitted. The use of NUCC and fittings
shall be permitted in the following:

(1) For direct burial underground installation (For
minimum cover requirements, see Table 300.5 and
Table 300.50 under Rigid NonmetaUic Conduit.)

(2) Encased or embedded in concrete

(3) In cinder fill

(4) In underground locations subject to severe corrosive
influences as covered in 300.6 and where subject to
chemicals for which the assembly is specifically
approved

(5) jteove^t^^ '-pm\kMi^^'\\n^^^
^^:^^^mm^_ :i^ss;||M50 .nam (2 ;y|.:of oog^^

2010 California Electrical Code

70-201

354.12

ARTICLE 354 -NONMETALLIC UNDERGROUND CONDUIT WITH CONDUCTORS: TYPE NUCC

354.12 Uses Not Permitted. NUCC shall not be used in
the following:

(1) In exposed locations

(2) Inside buildings

Exception: The conductor or the cable portion of the
assembly, where suitable, shall be permitted to extend
within the building for termination purposes in accordance
with 300.3.

(3) In btiy hazardous (classified) location, except as
permitted by otliei: articles of this Cof/e

354.20 Size.

(A) Minimum. NUCC smaller than metric designator 16
(trade size Vi) shall not be used.

(B) Maximum. NUCC larger than metric designator 103
(trade size 4) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

354.22 Number of Conductors. The number of
conductors or cables shall not exceed that permitted by the
percentage fill in Table 1, Chapter 9.

354.24 Bends — How Made. Bends shall be manually
made so that the conduit will not be damaged and the
internal diameter of the conduit will not be effectively
reduced. The radius of the curve of the centerline of such
bends shall not be less than shown in Table 354.24.

Table 354.24 Minimum Bending Radius for Nonmetallic
Underground Conduit with Conductors (NUCC)

Minimum Bending

Conduit Size

Radius

Metric

Designator

Trade Size

in.

'/2

250

300

350

450

V/2

500

650

900

1200

103

1500

354.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between termination points.

354.28 Trimming. For termination, the conduit shall be
trimmed away from the conductors or cables using an
approved method that will not damage the conductor or
cable insulation or jacket. All conduit ends shall be
trimmed inside and out to remove rough edges.

354.46 Busliings. Where the NUCC enters a box, fitting, or
other enclosure, a bushing or adapter shall be provided to
protect the conductor or cable from abrasion unless the design
of the box, fitting, or enclosure provides equivalent protection.

FPN: See 300:4(G) for the protection of conductors size 4
AWG or larger.

354.48 Joints. All joints between conduit, fittings, and
boxes shall be made by an approved method.

354.50 Conductor Terminations. All terminations between
the conductors or cables and equipment shall be made by an
approved method for that type of conductor or cable.

354.56 Splices and Taps. Splices and taps shall be made
injunction boxes or other enclosures.

354.60 Grounding. Where equipment grounding is
required, an assembly containing a separate equipment
grounding conductor shall be used.

III. Construction Specifications
354.100 Construction.

(A) General. NUCC is an assembly that is provided in
continuous lengths shipped in a coil, reel, or carton.

(B) Nonmetallic Underground Conduit. The nonmetallic
underground conduit shall be listed and composed of a
material that is resistant to moisture and corrosive agents. It
shall also be capable of being supplied on reels without
damage or distortion and shall be of sufficient strength to
withstand abuse, such as impact or crushing, in handling and
during installation without damage to conduit or conductors.

(C) Conductors and Cables. Conductors and cables used
in NUCC shall be Hsted and shall comply with 310.8(C).
Conductors of different systems shall be installed in
accordance with 300.3(C).

(D) Conductor Fill. The maximum number of conductors
or cables in NUCC shall not exceed that permitted by the
percentage fill in Table 1, Chapter 9.

354.120 Marking. NUCC shall be clearly and durably marked
at least every 3.05 m (10 ft) as required by 1 10.21. The type of
conduit material shall also be mcluded in the marking.

•

70-202

2010 California Electrical Code

ARTICLE 355 ~ REINFORCED THERMOSETTING RESIN CONDUIT; TYPE RTRC

355.20

Identification of conductors or cables used in the
assembly shall be provided on a tag attached to each end of
the assembly or to the side of a reel. Enclosed conductors
or cables shall be marked in accordance with 310.1 L

Reiiilprced Ther mosettiiig Resin Coiidiiit:

Type RTRC

I. General

355.1 Scope. This article covers the use, installation, and
construction specification for reinforced thermosetting
resin conduit (RTRC) and associated fittings.

FPN: Refer to Article 352 for Rigid Polyvinyl Chloride
Conduit: Type PVC, and Article 353 for High Density
Polyethylene Conduit: Type HDPE.

355.2 Definition.

Reinforced Thermosetting Resin Conduit (RTRC). A

rigid nonmetallic conduit (RNC) of circular cross section,
with integral or associated couplings, connectors, and fittings
for the installation of electrical conductors and cables.

355.6 Listing Requirements. RTRC, factory elbows, and
associated fittings shall be listed.

II. Installation

355.10 Uses Permitted. The use of RTRC shall be
permitted in accordance with 355.10(A) through (H).

(A) Concealed. RTRC shall be permitted in walls, floors,
and ceilings.

(B) Corrosive Influences. RTRC shall be permitted in
locations subject to severe corrosive influences as covered
in 300.6 and where subject to chemicals for which the
materials are specifically approved.

(D) Wet Locations. RTRC shall be permitted in portions
of dairies, laundries, canneries, or other wet locations, and
in locations where walls are frequently washed, the entire
;onduit system, including boxes and fittings used
.herewith, shall be installed and equipped so as to prevent
water from entering the conduit. All supports, bolts, straps,
screws, and so forth, shall be of corrosion-resistant
materials or be protected against corrosion by approved
corrosion-resistant materials.

(E) Dry and Damp Locations. RTRC shall be permitted for
use in dry and damp locations not prohibited by 355. 12.

(F) Exposed. RTRC shall be permitted for exposed work where
not subject to physical damage if identified for such use.

(G) Underground Installations. For underground installations,
see 300.5 and 300.50.

(H) Support of Conduit Bodies. RTRC shall be permitted to
support nonmetalHc conduit bodies not larger than the largest
trade size of an entering raceway. These conduit bodies shall not
support luminaires or other equipment and shall not contain
devices other than splicing devices as permitted by 110.14(B)
and 3 14.16(C)(2).

355.12 Uses Not Permitted.

under the following conditions.

RTRC shall not be used

(A) Hazardous (Classified) Locations.

(1) In any hazardous (classified) location, except as
permitted by other articles in this Code

(2) In Class I, Division 2 locations, except as permitted in
501.10(B)(3)

(B) Support of Luminaires. For the support of luminaires
or other equipment not described in 355.10(H).

(D) Ambient Temperatures. Where subject to ambient
temperatures in excess of 50'^C (122°F) unless listed
otherwise.

(E) Insulation Temperature Limitations. For conductors
or cables operating at a temperature higher than the RTRC
listed operating temperature rating.

Exception: Conductors or cables rated at a temperature
higher than the RTRC listed temperature rating shall be
permitted to be installed in RTRC, provided they are not
operated at a temperature higher than the RTRC listed
temperature rating.

(F) Theaters and Similar Locations. In theaters and
similar locations, except as provided in 518.4 and 520.5.

355.20 Size.

(A) Minimum. RTRC smaller than metric designator 16
(trade size Vi) shall not be used.

(B) Maximum. RTRC larger than metric designator 155
(trade size 6) shall not be used.

2010 California Electrical Code

70-203

355.22

ARTICLE 355 -REINFORCED THERMOSETTING RESIN CONDUIT: TYPE RTRC

FPN: The trade sizes and metric designators are for
identification purposes only and do not relate to actual
dimensions. See 300.1(C).

355.22 Number of Conductors. The number of conductors
shall not exceed that permitted by the percentage fill specified
in Table 1, Chapter 9. Cables shall be permitted to be installed
where such use is not prohibited by the respective cable
articles. The number of cables shall not exceed the allowable
percentage fill specified in Table 1, Chapter 9.

355.24 Bends - How Made. Bends shall be so made that
the conduit will not be damaged and the internal diameter of
the conduit will not be effectively reduced. Field bends shall
be made only with bending equipment identified for the
purpose. The radius of the curve to the centerline of such
bends shall not be less than shown in Table 2, Chapter 9.

355.26 Bends ~ Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

355.28 Trimming. All cut ends shall be trimmed inside
and outside to remove rough edges.

355.30 Securing and Supporting. RTRC shall be
installed as a complete system in accordance with 300.18
and shall be securely fastened in place and supported in
accordance with 355.30(A) and (B) or permitted to be
unsupported in accordance with 355.30(C).

(A) Securely Fastened. RTRC shall be securely fastened
within 900 mm (3 ft) of each outlet box, junction box,
device box, conduit body, or other conduit termination.
Conduit listed for securing at other than 900 mm (3 ft) shall
be permitted to be installed in accordance with the H sting.

(B) Supports. RTRC shall be supported as required in Table
355.30. Conduit listed for support at spacing other than as
shown in Table 355.30 shall be permitted to be installed in
accordance with the listing. Horizontal runs of RTRC
supported by openings through fi*aming members at intervals
not exceeding those in Table 355.30 and securely fastened
within 900 mm (3 ft) of termination points shall be permitted.

(C) Unsupported Raceways. Where oversized, concentric
or eccentric knockouts are not encountered. Type RTRC
shall be permitted to be unsupported where the raceway is
not more than 450 mm (18 in.) and remains in unbroken
lengths (without coupling). Such raceways shall terminate
in an outlet box, device box, cabinet, or other termination
at each end of the raceway.

355.44 Expansion Fittings. Expansion fittings for RTRC
shall be provided to compensate for thermal expansion and

Table 355.30 Support of Reinforced Thermosetting
Resin Conduit (RTRC)

Conduit Size

Maximum Spacing Between
Supports

Metric
Designator

16-27

35-53

63-78

91-129

155

Trade Size

Vi-i
VA-2

mm or m

900 mm
1.5 m
1.8 m
2.1m
2.5 m

contraction where the length change, in accordance with
Table 355.44, is expected to be 6 mm (!4 in.) or greater in a
straight run between securely mounted items such as boxes,
cabinets, elbows, or other conduit terminations.

355.46 Bushings. Where a conduit enters a box, fitting, or
other enclosure, a bushing or adapter shall be provided to
protect the wire fi*om abrasion unless the box, fitting, or
enclosure design provides equivalent protection.

FPN; See 300.4(G) for the protection of conductors 4 AWG
and larger at bushings.

355.48 Joints. All joints between lengths of conduit, and
between conduit and couplings, fitting, and boxes, shall be
made by an approved method.

355.56 Splices and Taps. Splices and taps shall be made
in accordance with 300.15.

355.60 Grounding. Where equipment grounding is
required, a separate equipment grounding conductor shall
be installed in the conduit.

Exception No. 1: As permitted in 250.134(B), Exception
No. 2, for dc circuits and 250.134(B), Exception No. 1, for
separately run equipment grounding conductors.

Exception No. 2: Where the grounded conductor is used to
ground equipment as permitted in 250. 142.

III. Construction Specifications

355.100 Construction. RTRC and fittings shall be composed of
suitable nonmetallic material that is resistant to moisture and
chemical atmospheres. For use aboveground, it shall also be
flame retardant, resistant to impact and crushing, resistant to
distortion fi*om heat under conditions likely to be encountered in
service, and resistant to low temperature and sunhght effects. For
use undergroimd, the material shall be acceptably resistant to
moisture and corrosive agents and shall be of sufficient strength to
withstand abuse, such as by impact and crushing, in handling and

•

70-204

2010 California Electrical Code

ARTICLE 356 - LIQUIDTIGHT FLEXIBLE NONMETALLIC CONDUIT: TYPE LFNC

356.2

Table 355.44 Expansion Characteristics of Reinforced Tiiermosetting Resin Conduit (RTRC) Coefficient of Thermal Expansion =
2.7 X 10-5 mm/mm/°C (1.5 x 10-5 in./in./°F)

Temperature
Change fC)

Length Change of

RTRC Conduit

(mm/m)

Temperature
Change (°F)

Length Change of

RTRC Conduit

(in./100 ft)

Temperature
Change (°F)

Length Change of

RTRC Conduit

(in./100 ft)

0.14

0.09

105

1.89

0.27

0.18

110

1.98

0.41

0.27

115

2.07

0.54

0.36

120

2.16

0.68

0.45

125

2.25

0.81

0.54

130

2.34

0.95

0.63

135

2.43

1.08

0.72

140

2.52

1.22

0.81

145

2.61

1.35

0.90

150

2.70

1.49

0.99

155

2.79

1.62

1.08

160

2.88

1.76

1.17

165

2.97

1.89

1.26

170

3.06

2.03

1.35

175

3.15

2.16

1.44

180

3.24

2.30

1.53

185

3.33

2.43

1.62

190

3.42

2.57

1.71

195

3.51

100

2.70

100

1.80

200

3.60

during installation. Where intended for direct burial,
without encasement in concrete, the material shall also be
capable of withstanding continued loading that is likely to
be encountered after installation.

355.120 Marking. Each length of RTRC shall be clearly
and durably marked at least every 3 m (10 ft) as required in
the first sentence of 110.21. The type of material shall also
be included in the marking unless it is visually identifiable.
For conduit recognized for use aboveground, these
markings shall be permanent. For conduit limited to
underground use only, these markings shall be sufficiently
durable to remain legible until the material is installed.
Conduit shall be permitted to be surface marked to indicate
special characteristics of the material.

FPN: Examples of these markings include but are not
limited to "limited smoke" and "sunlight resistant."

ARTICLE 356

Liquidtight flexible Nomnetallk Condtiit :

Ik;.;.' -^ ■ ■■ .: ..l-L^STP^LFNC./rk: = :'^..^^:::L£

I. General

356.1 Scope. This article covers the use, installation, and
construction specifications for liquidtight flexible
nonmetallic conduit (LFNC) and associated fittings.

356.2 Dennition.

Liquidtight Flexible NonmetalHc Conduit (LFNC). A
raceway of circular cross section of various types as
follows:

(1) A smooth seamless inner core and cover bonded
together and having one or more reinforcement layers
between the core and covers, designated as Type
LFNC-A

(2) A smooth inner surface with integral reinforcement
within the conduit wall, designated as Type LFNC-B

(3) A corrugated internal and external surface without
integral reinforcement within the conduit wall,
designated as LFNC-C

LFNC is flame resistant and with fittings and is approved
for the installation of electrical conductors.

FPN: FNMC is an altemative designation for LFNC.

2010 California Electrical Code

70-205

356.6

ARTICLE 356 -LIQUIDTIGHT FLEXIBLE NQNMETALLIC CONDUIT: TYPE LFNC

356.6 Listing Requirements.

fittings shall be listed.

LFNC and associated

II. Installation

356.10 Uses Permitted. LFNC shall be permitted to be used
in exposed or concealed locations for the following purposes:

FPN: Extreme cold may cause some types of nonmetallic
conduits to become brittle and therefore more susceptible to
damage from physical contact.

(1) Where flexibility is required for installation, operation,
or maintenance.

(2) Where protection of the contained conductors is
required from vapors, Hquids, or solids.

(3) For outdoor locations where listed and marked as
suitable for the purpose.

(4) For direct burial where listed and marked for the
purpose.

(5) Type LFNC-B shall be permitted to be installed in
lengths longer than 1 .8 m (6 ft) where secured in
accordance with 356.30.

(6) Type LFNC-B as a listed manufactured prewired
assembly, metric designator 1 6 through 27 (trade size
V2 through 1) conduit.

(7) For encasemeiit in Goncrete where listed for cHtect
biirial and jnsj^led in comgl w^e with 356 .42 ;

356.12 Uses Not Permitted. LFNC shall not be used as
follows:

(1) Where subject to physical damage

(2) Where any combination of ambient and conductor
temperatures is in excess of that for which the LFNC is
approved

(3) In lengths longer than 1.8 m (6 ft), except as permitted
by 356. 10(5) or where a longer length is approved as
essential for a required degree of flexibility

(4) Where the operating voltage of the contained
conductors is in excess of 600 volts, nominal, except
as permitted in 600.32(A)

(5) In any hazardous (classified) location, bccept as|
permtjed by other articles in ihbCqd^^

356.20 Size.

(A) Minimum. LFNC smaller than metric designator 16 (trade
size Yi) shall not be used unless permitted in 356.20(A)(1) or
(A)(2) for metric designator 12 (trade size 3/8).

(1) For enclosing the leads of motors as permitted in
430.245(B)

(2) In lengths not exceeding 1.8 m (6 ft ) as part of a listed
assembly for tap connections to luminaires as required
in 4l0.ln2(O' ^^ f*o^ utilization equipment

(B) Maximum, LFNC larger than metric designator 103
(trade size 4) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

356.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

Cables shall be permitted to be installed where such
use is not prohibited by the respective cable articles. The
number of cables shall not exceed the allowable percentage
fill specified in Table 1, Chapter 9.

356.24 Bends — How Made. Bends in conduit shall be so
made that the conduit is not damaged and the internal
diameter of the conduit is not effectively reduced. Bends
shall be permitted to be made manually without auxiliary
equipment. The radius of the curve to the centerline of any
bend shall not be less than shown in Table 2, Chapter 9
using the column "Other Bends."

356.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

356.28 Trimming. All cut ends of conduit shall be
trimmed inside and outside to remove rough edges.

356.30 Securing and Supporting. Type LFNC-B shall be
securely fastened and supported in accordance with one of
the following:

(1) Where installed in lengths exceeding 1.8 m (6 ft), the
conduit shall be securely fastened at intervals not
exceeding 900 mm (3 ft) and within 300 mm (12 in.) on
each side of every outlet box, junction box, cabinet, or
fitting.

(2) Securing or supporting of the conduit shall not be required
where it is fished, installed in lengths not exceeding 900
mm (3 ft) at terminals where flexibiUty is required, or
installed in lengths not exceeding 1.8 m (6 ft) from a
luminaire terminal connection for tap conductors to
luminaires permitted in 4 1 0.1 1 7(C).

(3) Horizontal runs of LFNC supported by openings through
framing members at intervals not exceeding 900 mm (3 ft)
and securely fastened within 300 mm (12 in.) of
termination points shall be permitted.

(4) Securing or supporting of LFNC-B shall not be required
where installed in lengths not exceeding 1.8 m (6 ft) from
the last point where the raceway is securely fastened for
connections within an accessible ceiling to luminau'e(s) or
other equipment.

70-206

2010 California Electrical Code

ARTICLE 358 - ELECTRICAL METALLIC TUBING: TYPE EMT

358.20

356.42 Couplings and Connectors. Only fittings listed for use
with LFNC shall be used. Angle connectors shall not be used
for concealed raceway installations. Straight LFNC fittings are
permitted for direct burial or encasement in concrete.

356.56 Splices and Taps. Splices and taps shall be made
in accordance with 300.15.

356.60 Grounding and Bonding. Where used to connect
equipment where flexibility is required, an equipment
grounding conductor shall be installed.

Where required or installed, equipment grounding
conductors shall be installed in accordance with

250.134(B).

Where required or installed, equipment bonding jumpers
shall be installed in accordance with 250.102.

III. Construction Specifications

356.100 Construction. LFNC-B as a prewired
manufactured assembly shall be provided in continuous
lengths capable of being shipped in a coil, reel, or carton
without damage.

356.120 Marking. LFNC shall be marked at least every
600 mm (2 ft) in accordance with 110.21. The marking
shall include a type designation in accordance with 356.2
and the trade size. Conduit that is intended for outdoor use
or direct burial shall be marked.

The type, size, and quantity of conductors used in
prewired manufactured assemblies shall be identified by
means of a printed tag or label attached to each end of the
manufactured assembly and either the carton, coil, or reel.
The enclosed conductors shall be marked in accordance
with 310.11.

■ ■ ■ ' . ■ . Electrical Metallic Tubiiig: 'Type lEMt ; ■ . ■

I. General

358.1 Scope. This article covers the use, installation, and
construction specifications for electrical metallic tubing
(EMT) and associated fittings.

358.2 Definition.

Electrical Metallic Tubing (EMT). An unthreaded thinwall
raceway of circular cross section designed for the physical
protection and routing of conductors and cables and for use
as an equipment grounding conductor when installed
utilizing appropriate fittings. EMT is generally made of
steel (ferrous) with protective coatings or aluminum
(nonferrous).

358.6 Listing Requirements. EMT, factory elbows, and
associated fittings shall be listed.

II. Installation

358.10 Uses Permitted.

(A) Exposed and Concealed. The use of EMT shall be
permitted for both exposed and concealed work.

(B) Corrosion Protection. Ferrous or nonferrous EMT,
elbows, couplings, and fittings shall be permitted to be
installed in concrete, in direct contact with the earth, or in
areas subject to severe corrosive influences where protected
by corrosion protection and judged suitable for the condition.

(C) Wet Locations. All supports, bolts, straps, screws, and
so forth shall be of corrosion-resistant materials or
protected against corrosion by corrosion-resistant materials.

FPN: See 300.6 for protection against corrosion.

358.12 Uses Not Permitted. EMT shall not be used under
the following conditions:

(1) Where, during installation or afterward, it will be
subject to severe physical damage.

(2) Where protected from corrosion solely by enamel.

(3) In cinder concrete or cinder fill where subject to
permanent moisture unless protected on all sides by a
layer of noncinder concrete at least 50 mm (2 in.) thick
or unless the tubing is at least 450 mm (18 in.) under
the fill.

(4) In any hazardous (classified) location except as
permitted by j6ther:aWi;cle$:iB iimCdde.

(5) For the support of luminaires or other equipment
except conduit bodies no larger than the largest trade
size of the tubing.

(6) Where practicable, dissimilar metals in contact
anywhere in the system shall be avoided to eliminate
the possibility of galvanic action.

Exception: Aluminum fittings and enclosures shall be
permitted to he used with steel EMT where not subject to
severe corrosive influences.

358.20 Size.

(A) Minimum. EMT smaller than metric designator 16
(trade size Vi) shall not be used.

2010 California Electrical Code

70-207

358.22

ARTICLE 360 -FLEXIBLE METALLIC TUBING: TYPE FMT

Exception: For enclosing the leads of motors as permitted
in 430.245(B).

(B) Maximum. The maximum size of EMT shall be metric
designator 103 (trade size 4).

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

358.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill specified in Table 1, Chapter 9.

358.24 Bends — How Made. Bends shall be made so that
the tubing is not damaged and the internal diameter of the
tubing is not effectively reduced. The radius of the curve of
any field bend to the centerline of the tubing shall not be
less than shown in Table 2, Chapter 9 for one-shot and full
shoe benders.

358.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

358.28 Reaming and Threading.

(A) Reaming. All cut ends of EMT shall be reamed or
otherwise finished to remove rough edges.

(B) Tlireading. EMT shall not be threaded.

Exception: EMT with factory threaded integral couplings
complying with 358.100.

358.30 Securing and Supporting. EMT shall be installed
as a complete system in accordance with 300.18 and shall
be securely fastened in place and supported in accordance
with 358.30(A) and (B) or perrnitteil to be uhsuppprted in
accordance with 358.30(C).

(A) Securely Fastened. EMT shall be securely fastened in
place at least every 3 m (10 ft). In addition, each EMT run
between termination points shall be securely fastened
within 900 mm (3 ft) of each outlet box, junction box,
device box, cabinet, conduit body, or other tubing
termination.

Exception No. 1: Fastening of unbroken lengths shall be
permitted to be increased to a distance of 1.5 m (5 ft)
where structural members do not readily permit fastening
within 900 mm (3 ft).

Exception No. 2: For concealed work in finished buildings
or prefinished wall panels where such securing is

impracticable, unbroken lengths (without coupling) of EMT
shall be permitted to be fished.

(B) Supports. Horizontal runs of EMT supported by
openings through framing members at intervals not greater
than 3 m (10 ft) and securely fastened within 900 mm (3 ft)
of termination points shall be permitted.

(C) :tlBSiippprted Raceways.: Whaire^ avei^ized, 'cptxcQuinp.
pt: eccentric: iaiockou|s..are.pot ^encountered. Type -EMT
shall be pertoitted to be misuppoited wte^^ raceway i^
ii&t^.iMr^,:tM ni|i^|i|an.)__ andjre^

lengths (mXhouim §ijch raceways s^^^

ih an outlet box^ device Jipx^ cabinet, or 6t%r term

^teach end ot tlie. raceway;

358.42 Couplings and Connectors. Couplings and
connectors used with EMT shall be made up tight. Where
buried in masonry or concrete, they shall be concretetight
type. Where installed in wet locations, they shall comply
with 314.15.

358.56 Splices and Taps. Sphces and taps shall be made
in accordance with 300.15.

358.60 Grounding. EMT shall be permitted as an
equipment grounding conductor.

III. Construction Specifications

358.100 Construction. Factory-threaded integral

couplings shall be permitted. Where EMT with a threaded
integral coupling is used, threads for both the tubing and
coupling shall be factory-made. The coupling and EMT
threads shall be designed so as to prevent bending of the
tubing at any part of the thread.

358.120 Marking. EMT shall be clearly and durably
marked at least every 3 m (10 ft) as required in the first
sentence of 110.21.

ARTICLE 360

Flexible Metallic Tubing: Type FMT

I. General

360.1 Scope. This article covers the use, installation, and
construction specifications for flexible metallic tubing
(FMT) and associated fittings.

360.2 Definition.

Flexible Metalhc Tubing (FMT). A raceway that is circular
in cross section, flexible, metalhc, and hquidtight without a
nonmetallic jacket.

70-208

2010 California Electrical Code

ARTICLE 360 - FLEXIBLE METALLIC TUBING: TYPE FMT

360.120

360.6 Listing Requirements. FMT and associated fittings
shall be listed.

11. Installation

360.10 Uses Permitted. FMT shall be permitted to be
used for branch circuits as follows:

(1) In dry locations

(2) Where concealed

(3) In accessible locations

(4) For system voltages of 1000 volts maximum

360.12 Uses Not Permitted. FMT shall not be used as
follows:

(1) In hoistways

(2) In storage battery rooms

(3) In hazardous (classified) locations unless otherwise
permitted under other articles in this Code

(4) Underground for direct earth burial, or embedded in
poured concrete or aggregate

(5) Where subject to physical damage

(6) In lengths over 1.8 m (6 ft)
360.20 Size.

(A) Minimum. FMT smaller than metric designator 16
(trade size V2) shall not be used.

Exception No. 1: FMT of metric designator 12 (trade size
3/8) shall he permitted to be installed in accordance with
300.22(B) and (C).

Exception No. 2: FMT of metric designator 12 (trade size 3/8)
shall be permitted in lengths not in excess of 1.8 m (6 ft) as
part of a listed assembly or for luminaires. See 41 Oil 17(C).

(B) Maximum. The maximum size of FMT shall be metric
designator 21 (trade size Va).

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

360.22 Number of Conductors.

(A) FMT — Metric Designators 16 and 21 (Trade Sizes

Vi and V4), The number of conductors in metric designators
1 6 (trade size Vi) and 2 1 (trade size Va) shall not exceed that
permitted by the percentage fill specified in Table 1,
Chapter 9.

Cables shall be permitted to be installed where such
use is not prohibited by the respective cable articles. The

number of cables shall not exceed the allowable percentage
fill specified in Table 1, Chapter 9.

(B) FMT — Metric Designator 12 (Trade Size 3/8). The

number of conductors in metric designator 12 (trade size
3/8) shall not exceed that permitted in Table 348.22,

360.24 Bends.

(A) Infrequent Flexing Use. Where FMT may be

infrequently flexed in service after installation, the radii of
bends measured to the inside of the bend shall not be less
than specified in Table 360.24(A).

Table 360.24(A) Minimum Radii for Flexing Use

Minimum Radii for Flexing
Use

Metric

j^esignaiur

Trade Size

in.

25.4

317.5

12'/2

444.5

17^2

(B) Fixed Bends. Where FMT is bent for installation
purposes and is not flexed or bent as required by use after
installation, the radii of bends measured to the inside of the
bend shall not be less than specified in Table 360.24(B).

Table 360.24(B) Minimum Radii for Fixed Bends

Trade Size

Minimum Radii for Fixed
Bends

Metric
Designator

in.

12
16
21

88.9
101.6
127.0

V/2

4
5

360.40 Boxes and Fittings. Fittings shall effectively close
any openings in the connection.

360.56 Splices and Taps. Splices and taps shall be made
in accordance with 300. 15.

360.60 Grounding. FMT shall be permitted as an
equipment grounding conductor where installed in
accordance with 250.1 18(7).

TIL Construction Specifications

360.120 Marking. FMT shall be marked according to 1 10.21.

2010 California Electrical Code

70-209

362.1

ARTICLE 362 -ELECTRICAL NONMETALLIC TUBING: TYPE ENT

I. General

362.1 Scope. This article covers the use, installation, and
construction specifications for electrical nonmetallic tubing
(ENT) and associated fittings.

362.2 Definition.

Electrical Nonmetallic Tubing (ENT). A nonmetallic,
pliable, corrugated raceway of circular cross section with
integral or associated couplings, connectors, and fittings for
the installation of electrical conductors. ENT is composed
of a material that is resistant to moisture and chemical
atmospheres and is flame retardant.

A pliable raceway is a raceway that can be bent by
hand with a reasonable force but without other assistance.

362.6 Listing Requirements. ENT and associated fittings
shall be listed.

II. Installation

362.10 Uses Permitted. For the purpose of this article, the
first floor of a building shall be that floor that has 50
percent or more of the exterior wall surface area level with
or above finished grade. One additional level that is the
first level and not designed for human habitation and used
only for vehicle parking, storage, or similar use shall be
permitted. The use of ENT and fittings shall be permitted
in the following:

(1) In any building not exceeding three floors above grade
as follows:

a. For exposed work, where not prohibited by 362.12

b. Concealed within walls, floors, and ceilings

(2) In any building exceeding three floors above grade,
ENT shall be concealed within walls, floors, and
ceilings where the walls, floors, and ceilings provide a
thermal barrier of material that has at least a 15 -minute
finish rating as identified in listings of fire-rated
assemblies. The 15 -minute-finish-rated thermal barrier
shall be permitted to be used for combustible or
noncombustible walls, floors, and ceilings.

Exception to (2): Where a fire sprinkler system(s) is
installed in accordance with NFPA 13-2007, Standard for
the Installation of Sprinkler Systems, on all floors, ENT
shall be permitted to be used within walls, floors, and
ceilings, exposed or concealed, in buildings exceeding
three floors abovegrade.

FPN: A finish rating is established for assemblies
containing combustible (wood) supports. The finish rating
is defined as the time at which the wood stud or wood joist
reaches an average temperature rise of 121°C (250°F) or an

individual temperature of 163°C (325°F) as measured on
the plane of the wood nearest the fire. A finish rating is not
intended to represent a rating for a membrane ceiling.

(3) In locations subject to severe corrosive influences as
covered in 300.6 and where subject to chemicals for which
the materials are specifically approved.

(4) In concealed, dry, and damp locations not prohibited by
362.12.

(5) Above suspended ceilings where the suspended ceilings
provide a thermal barrier of material that has at least a 15-
minute finish rating as identified in listings of fire-rated
assemblies, except as permitted in 362.10(l)(a).

Exception to (5): ENT shall be permitted to be used above
suspended ceilings in buildings exceeding three floors
above grade where the building is protected throughout by
afire sprinkler system installed in accordance with NFPA
13-2007, Standard for the Installation of Sprinkler Systems.

(6) Encased in poured concrete, or embedded in a concrete
slab on grade ivhere ENT is placed on sand or
approved screenings, provided fittings identified for
this purpose are used for connections.

(7) For wet locations indoors as permitted in this section or
in a concrete slab on or belowgrade, with fittings Hsted
for the purpose.

(8) Metric designator 16 through 27 (trade size Vi through
1) as listed manufactured prewired assembly.

FPN: Extreme cold may cause some types of nonmetallic
conduits to become brittle and therefore more susceptible to
damage from physical contact.

362.12 Uses Not Permitted. ENT shall not be used in the
following:

(1) In §if hazardous (classified) location, except as
permitted by &iheilarticlgs in^ ^^

(2) For the support of luminaires and other equipment

(3) Where subject to ambient temperatures in excess of
50°C (122°F) unless Hsted otherwise

(4) For conductors or cables operating at a temperature
higher than the ENT listed temperature rating

Exception to (4): Conductors or cables rated at a
temperature higher than the ENT listed temperature rating
shall be permitted to be installed in ENT, provided they are
not operated at a temperature higher than the ENT listed
temperature rating.

(5) For direct earth burial

(6) Where the voltage is over 600 volts

(7) In exposed locations, except as permitted by 362.10(1),

362.10(5), and 362.10(7)

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2010 Califomia Electrical Code

ARTICLE 362 - ELECTRICAL NONMETALLIC TUBING: TYPE ENT

362.120

(8) In theaters and similar locations, except as provided in
518.4 and 520.5

(9) Where exposed to the direct rays of the sun, unless
identified as sunlight resistant

(10) Where subject to physical damage
362.20 Size.

(A) Minimum. ENT smaller than metric designator 16
(trade size Vi) shall not be used.

(B) Maximum. ENT larger than metric designator 53
(trade size 2) shall not be used.

FPN: See 300.1(C) for the metric designators and trade
sizes. These are for identification purposes only and do not
relate to actual dimensions.

362.22 Number of Conductors. The number of
conductors shall not exceed that permitted by the
percentage fill in Table 1, Chapter 9.

362.24 Bends — How Made. Bends shall be so made that
the tubing will not be damaged and the internal diameter of
the tubing will not be effectively reduced. Bends shall be
permitted to be made manually without auxiliary
equipment, and the radius of the curve to the centerline of
such bends shall not be less than shown in Table 2, Chapter
9 using the column "Other Bends,"

362.26 Bends — Number in One Run. There shall not be
more than the equivalent of four quarter bends (360
degrees total) between pull points, for example, conduit
bodies and boxes.

362.28 Trimming. All cut ends shall be trimmed inside
and outside to remove rough edges.

362.30 Securing and Supporting. ENT shall be installed
as a complete system in accordance with 300.18 and shall
be securely fastened in place and supported in accordance
with 362.30(A) and (B).

(A) Securely Fastened. ENT shall be securely fastened at
intervals not exceeding 900 mm (3 ft). In addition, ENT
shall be securely fastened in place within 900 mm (3 ft) of
each outlet box, device box, junction box, cabinet, or fitting
where it terminates.

Exception No, I: Lengths not exceeding a distance of 1.8
m (6 ft) from a luminaire terminal connection for tap
connections to lighting luminaires shall he permitted

without being secured.

Exception No. 2: Lengths not exceeding L8 m (6 ft) from
the last point where the raceway is securely fastened for
connections within an accessible ceiling to luminaire(s) or
other equipment.

Exception No. 3: For concealed work in finished bmldings
or. prefinisked yvaii panels where .such securing is
impracticable, vnhroken lengths (without coupling) of ENT
shall be permitted to be fished

(B) Supports. Horizontal runs of ENT supported by
openings in framing members at intervals not exceeding
900 mm (3 ft) and securely fastened within 900 mm (3 ft)
of termination points shall be permitted.

362.46 Bushings. Where a tubing enters a box, fitting, or
other enclosure, a bushing or adapter shall be provided to
protect the wire from abrasion unless the box, fitting, or
enclosure design provides equivalent protection.

FPN: See 300.4(G) for the protection of conductors size 4
AWG or larger.

362.48 Joints. All joints between lengths of tubing and
between tubing and couplings, fittings, and boxes shall be
by an approved method.

362.56 Splices and Taps. Splices and taps shall be made
only in accordance with 300.15.

FPN: See Article 3 14 for rules on the installation and use of
boxes and conduit bodies.

362.60 Grounding. Where equipment grounding is
required, a separate equipment grounding conductor shall
be installed in the raceway in compliancg ^dth Artk^ 250;
Pail; VI;

III. Construction Specifications

362.100 Construction. ENT shall be made of material that
does not exceed the ignitibility, flammability, smoke
generation, and toxicity characteristics of rigid
(nonplasticized) polyvinyl chloride.

ENT, as a prewired manufactured assembly, shall be
provided in continuous lengths capable of being shipped in
a coil, reel, or carton without damage.

362.120 Marldng. ENT shall be clearly and durably
marked at least every 3 m (10 ft) as required in the first
sentence of 110.21. The type of material shall also be
included in the marking. Marking for limited smoke shall
be permitted on the tubing that has limited smoke-
producing characteristics.

2010 California Electrical Code

70-211

366.1

ARTICLE 366 -AUXILIARY GUTTERS

Auxiliary Gutters

I. General

366.1 Scope. This article covers the use, installation, and
construction requirements of metal auxiliary gutters and
nonmetallic auxiliary gutters and associated fittings.

366.2 Definitions.

Metallic Auxiliary Gutter. A sheet metal enclosure used
to supplement wiring spaces at m^ter centers, distiibi^itioti
jcenters; switchboards, and similar points of wiriiig systems.
The enclosure has hinged ox jretnovable covers for housing
and protecting electrical wires^ cable, and busbars: The
enclosure is designed for conductors to be laid or set inj
place after the enclosures have l^een installed as a complete
systerril

Nonmetallic Auxiliary Gutter. A flame i^etardaatj-
nonmetallic enclosure used to supplement wiring spaces a^
meter centers, distribution; centers, switcliboardsi V^Piid
similar points of v;^iring systenas* The enclosure has hinged
or removable covers for housing and ptotecting electrical
wires, cable, and busbars. The enclosure is designed fdd
/conductors to be laid or set -inTplace after the^e^^^
kaye been installed as a coniplbte systetnl

366.6 Listing Requirements.

(A) Outdoors. Nonmetallic auxiliary gutters installed
outdoors shall comply with the following:

(1) Be listed as suitable for exposure to sunUght

(2) Be listed as suitable for use in wet locations

(3) Be listed for maximum ambient temperature of the
installation

(B) Indoors. Nonmetallic auxihary gutters installed
indoors shall be listed for the maximum ambient
temperature of the installation.

II. Installation
366.10 Uses Permitted.

m
(A) Sheet Metal Auxiliary Gutters.

(1) Indoor and Outdoor Use. Sheet metal auxiliary
gutters shall be permitted for indoor and outdoor use.

(2) Wet Locations. Sheet metal auxiliary gutters installed
in wet locations shall be suitable for such locations.

(B) Nonmetallic Auxiliary Gutters. Nonmetallic auxiliary
gutters shall be listed for the maximum ambient
temperature of the installation and marked for the installed
conductor insulation temperature rating.

(1) Outdoors. Nonmetallic auxiliary gutters shall be
permitted to be installed outdoors where listed and marked
as suitable for the purpose.

FPN: Extreme cold may cause nonmetallic auxiliary gutters
to become brittle and therefore more susceptible to damage
from physical contact.

(2) Indoors. Nonmetallic auxiliary gutters shall be
permitted to be installed indoors.

366.12 Uses Not Permitted. Auxiliary gutters shall not be
used under the following conditions:

(1) To enclose switches, overcurrent devices, appHances,
or other similar equipment

(2) To extend a greater distance than 9 m (30 ft) beyond
the equipment that it supplements

Exception: As permitted in 620.35 for elevators, an
auxiliary gutter shall be permitted to extend a distance
greater than 9 m (30 ft) beyond the equipment it
supplements.

FPN: For wireways, see Articles 376 and 378. For busways,

see Article 368.

366.22 Number of Conductors.

(A) Sheet Metal Auxiliary Gutters. The sum of the cross-
sectional areas of all contained conductors at any cross
section of a sheet metal auxiliary gutter shall not exceed 20
percent of the interior cross-sectional area of the sheet
metal auxiliary gutter. The derating factors in
310.15(B)(2)(a) shall be applied only where the number of
current-carrying conductors, including neutral conductors
classified as current-carrying under the provisions of
310.15(B)(4), exceeds 30. Conductors for signaling circuits
or controller conductors between a motor and its starter and
used only for starting duty shall not be considered as
current-carrying conductors.

(B) Nonmetallic Auxiliary Gutters. The sum of cross-
sectional areas of all contained conductors at any cross
section of the nonmetallic auxiliary gutter shall not exceed
20 percent of the interior cross-sectional area of the
nonmetallic auxiliary gutter.

366.23 Ampacity of Conductors.

(A) Sheet Metal Auxiliary Gutters. Where the number of
current-carrying conductors contained in the sheet metal
auxiliary gutter is 30 or less, the |dj:U|tmeiit factors
specified in 310.15(B)(2)(a) shall not apply. The current
carried continuously in bare copper bars in sheet metal
auxiliary gutters shall not exceed 1.55 amperes/mm2 (1000
amperes/in.2) of cross section of the conductor. For
aluminum bars, the current carried continuously shall not
exceed 1.09 amperes/mm2 (700 amperes/in.2) of cross
section of the conductor.

70-212

2010 Califomia Electrical Code

ARTICLE 366 - AUXILIARY GUTTERS

366.120

(B) Nonmetallic Auxiliary Gutters. The derating factors
specified in 310.15(B)(2)(a) shall be applicable to the
current-carrying conductors in the nonmetallic auxiliary
gutter.

366.30 Securing and Supporting.

(A) Sheet Metal Auxiliary Gutters. Sheet metal auxiliary
gutters shall be supported throughout their entire length at
intervals not exceeding 1.5 m (5 ft).

(B) Nonmetallic Auxiliary Gutters. Nonmetallic auxiliary
gutters shall be supported at intervals not to exceed 900
mm (3 ft) and at each end or joint, unless listed for other
support intervals. In no case shall the distance between
supports exceed 3 m (10 ft).

366.44 Expansion Fittings. Expansion fittings shall be
installed where expected length change, due to expansion
and contraction due to temperature change, is more than 6
mm (0.25 in.).

366.56 Splices and Taps. Splices and taps shall comply
with 366.56(A) through (D).

(A) Within Gutters. Splices or taps shall be permitted
within gutters where they are accessible by means of
removable covers or doors. The conductors, including
splices and taps, shall not fill the gutter to more than 75
percent of its area.

(B) Bare Conductors. Taps from bare conductors shall
leave the gutter opposite their terminal connections, and
conductors shall not be brought in contact with uninsulated
current-carrying parts of different potential.

(C) Suitably Identified. All taps shall be suitably
identified at the gutter as to the circuit or equipment that
they supply.

(D) Overcurrent Protection. Tap connections from
conductors in auxiliary gutters shall be provided with
overcurrent protection as required in 240.21.

366.58 Insulated Conductors.

(A) Deflected Insulated Conductors. Where insulated
conductors are deflected within an auxiliary gutter, either at
the ends or where conduits, fittings, or other raceways or
cables enter or leave the gutter, or where the direction of
the gutter is deflected greater than 30 degrees, dimensions
corresponding to one wire per terminal in Table 312.6(A)
shall apply.

(B) Auxiliary Gutters Used as Pull Boxes. Where
insulated conductors 4 AWG or larger are pulled through
an auxiliary gutter, the distance between raceway and cable

entries enclosing the same conductor shall not be less than
that required in 314,28(A)(1) for straight pulls and
314.28(A)(2) for angle pulls.

366.60 Grounding. Metal auxiliary gutters shall be
Qomecie&jq m^e^^

Iquipmept !?OT^ or to j the groiinded couiiwtoi

Wh^pi^rr^^^ or mqiSedby 250.92(B)(1^^

III. Construction Specifications
366.100 Construction.

(A) Electrical and Mechanical Continuity. Gutters shall
be constructed and installed so that adequate electrical and
mechanical continuity of the complete system is secured.

(B) Substantial Construction. Gutters shall be of
substantial construction and shall provide a complete
enclosure for the contained conductors. All surfaces, both
interior and exterior, shall be suitably protected from
corrosion. Comer joints shall be made tight, and where the
assembly is held together by rivets, bolts, or screws, such
fasteners shall be spaced not more than 300 mm (12 in.)
apart.

(C) Smooth Rounded Edges. Suitable bushings, shields,
or fittings having smooth, rounded edges shall be provided
where conductors pass between gutters, through partitions,
around bends, between gutters and cabinets or junction
boxes, and at other locations where necessary to prevent
abrasion of the insulation of the conductors.

(D) Covers. Covers shall be securely fastened to the gutter.

(E) Clearance of Bare Live Parts. Bare conductors shall
be securely and rigidly supported so that the minimum
clearance between bare current-carrying metal parts of
different potential mounted on the same surface will not be
less than 50 mm (2 in.), nor less than 25 mm (1 in.) for
parts that are held free in the air. A clearance not less than
25 mm (I in.) shall be secured between bare current-
carrying metal parts and any metal surface. Adequate
provisions shall be made for the expansion and contraction
of busbars.

366.120 Marking.

(A) Outdoors. Nonmetallic auxiliary gutters installed
outdoors shall have the following markings:

(1) Suitable for exposure to sunlight

(2) Suitable for use in wet locations

(3) Installed conductor insulation temperature rating

2010 California Electrical Code

70-213

368.1

ARTICLE 368 - BUSWAYS

(B) Indoors. Nonmetallic auxiliary gutters installed
indoors shall have the following markings:

(1) Installed conductor insulation temperature rating

^{'■^Jk ^ ■ -D .ARTICLE '3^8; :';;-^ ■■■:;/■::■:.

[- . .'; : ■■.■■;■'■ Busways ■ : ■ ■ ■■;

I. General Requirements

368.1 Scope. This article covers service-entrance, feeder,
and branch-circuit busways and associated fittings.

368.2 Definition.

Busway. A grounded metal enclosure containing factory-
mounted, bare or insulated conductors, which are usually
copper or aluminum bars, rods, or tubes.

FPN: For cablebus, refer to Article 370.

II. Installation

368.10 Uses Permitted. Busways shall be permitted to be
installed where they are located in accordance with
368.10(A) through (C).

(A) Exposed. Busways shall be permitted to be located in
the open where visible, except as permitted in 368. 10(C).

(B) Concealed. Busways shall be permitted to be installed
behind access panels, provided the busways are totally
enclosed, of nonventilating-type construction, and installed
so that the joints between sections and at fittings are
accessible for maintenance purposes. Where installed
behind access panels, means of access shall be provided,
and either of the following conditions shall be met:

(1) The space behind the access panels shall not be used
for air-handling purposes.

(2) Where the space behind the access panels is used for
environmental air, other than ducts and plenums, there
shall be no provisions for plug-in connections, and the
conductors shall be insulated.

(C) Through Walls and Floors. Busways shall be
permitted to be installed through walls or floors in
accordance with (C)(1) and (C)(2).

(1) Walls. Unbroken lengths of busway shall be permitted
to be extended through dry walls.

(2) Floors. Floor penetrations shall comply with (a) and (b):

(a) Busways shall be permitted to be extended
vertically through dry floors if totally enclosed
(unventilated) where passing through and for a minimum

distance of 1.8 m (6 ft) above the floor to provide adequate
protection from physical damage.

(b) In other than industrial establishments, where a
vertical riser penetrates two or more dry floors, a minimum
100-mm (4-in.) high curb shall be installed around all floor
openings for riser busways to prevent liquids from entering
the opening. The curb shall be installed within 300 mm (12
in.) of the floor opening. Electrical equipment shall be
located so that it will not be damaged by liquids that are
retained by the curb.

FPN: See 300.21 for information concerning the spread of
fire or products of combustion.

368.12 Uses Not Permitted.

(A) Physical Damage. Busways shall not be installed
where subject to severe physical damage or corrosive
vapors.

(B) Hoistways. Busways shall not be installed in
hoistways.

(C) Hazardous Locations. Busways shall not be installed
in any hazardous (classified) location, unless specifically
approved for such use.

FPN: See 501.10(B).

(D) Wet Locations. Busways shall not be installed
outdoors or in wet or damp locations unless identified for
such use.

(E) Working Platform. Lighting busway and trolley
busway shall not be installed less than 2.5 m (8 ft) above
the floor or working platform unless provided with a cover
identified for the purpose.

368.17 Overcurrent Protection. Overcurrent protection shall
be provided in accordance with 368.17(A) through (D).

(A) Rating of Overcurrent Protection — Feeders. A

busway shall be protected against overcurrent in
accordance with the allowable current rating of the busway.

Exception No. 1: The applicable provisions of 240.4 shall
he permitted.

Exception No. 2: Where used as transformer secondary
ties, the provisions of 450.6(A)(3) shall be permitted.

(B) Reduction in Ampacity Size of Busway. Overcurrent
protection shall be required where busways are reduced in
ampacity.

Exception: For industrial establishments only, omission of
overcurrent protection shall be permitted at points where
busways are reduced in ampacity, provided that the length
of the busway having the smaller ampacity does not exceed
15 m (50 ft) and has an ampacity at least equal to one-third
the rating or setting of the overcurrent device next back on
the line, and provided that such busway is free from
contact with combustible material.

•

70-214

2010 California Electrical Code

ARTICLE 368 - BUSWAYS

368.234

(C) Feeder or Branch Circuits. Where a busway is used
as a feeder, devices or plug-in connections for tapping off
feeder or branch circuits from the busway shall contain the
overcurrent devices required for the protection of the feeder
or branch circuits. The plug-in device shall consist of an
externally operable circuit breaker or an externally
operable fusible switch. Where such devices are mounted
out of reach and contain disconnecting means, suitable
means such as ropes, chains, or sticks shall be provided for
operating the disconnecting means from the floor.
Exception No. 1: As permitted in 240.21.

Exception No. 2: For fixed or semifixed luminaires, where
the branch- circuit overcurrent device is part of the
luminaire cord plug on cord-connected luminaires.
Exception No. 3: Where luminaires without cords are
plugged directly into the busway and the overcurrent
device is mounted on the luminaire.

(D) Rating of Overcurrent Protection — BrancJi
Circuits. A busway used as a branch circuit shall be
protected against overcurrent in accordance with 210.20.
368.30 Support. Busways shall be securely supported at
intervals not exceeding 1.5 m (5 ft) unless otherwise
designed and marked.

368.56 Branches from Busways. Branches from busways
shall be permitted to be made in accordance with
368.56(A), (B), and (C).

(A) General. Branches from busways shall be permitted to
use any of the following wiring methods:

1) Type AC armored cable

2) Type MC metal-clad cable

3) Type MI mineral-insulated, metal-sheathed cable

4) Type IMC intermediate metal conduit

5) Type RMC rigid metal conduit

6) Type FMC flexible metal conduit

7) Type LFMC liquidtight flexible metal conduit

8) Type WC rigid p(>lyvinyl chloride conduit

9) Type RTRC remfof ced thermosgk^^^

I) TypelLFNCliqiiidtight flexible a^^ conduit Q

II) Type EMT electrical metaUic tubing

12) Type ENT electrical nonmetaUic tubing

13) Busways

14) Strut-type channel raceway

15) Surface metal raceway

16) Surface nonmetaUic raceway

Where a separate equipment grounding conductor is used,
connection of the equipment grounding conductor to the
busway shall comply with 250.8 and 250.12.

(B) Cord and Cable Assemblies. Suitable cord and cable
assemblies approved for extra-hard usage or hard usage and
listed bus drop cable shall be permitted as branches from
busways for the connection of portable equipment or the

connection of stationary equipment to facilitate their
interchange in accordance with 400.7 and 400.8 and the
following conditions:

(1) The cord or cable shall be attached to the building by
an approved means.

(2) The length of the cord or cable from a busway plug-in
device to a suitable tension take-up support device
shall not exceed 1 .8 m (6 ft).

(3) The cord and cable shall be installed as a vertical riser
from the tension take-up support device to the
equipment served.

(4) Strain relief cable grips shall be provided for the cord
or cable at the busway plug-in device and equipment
terminations.

Exception to (B)(2): In industrial establishments only,
where the conditions of maintenance and supervision
ensure that only qualified persons service the installation,
lengths exceeding 1.8 m (6 ft) shall be permitted beP\^^een
the busway plug-in device and the tension take-up support
device where the cord or cable is supported at intervals not
exceeding 2.5 m (8 ft).

(C) Branches from Trolley-Type Busways. Suitable cord
and cable assemblies approved for extra-hard usage or hard
usage and listed bus drop cable shall be permitted as
branches from trolley-type busways for the connection of
movable equipment in accordance with 400.7 and 400.8.
368.58 Dead Ends. A dead end of a busway shall be
closed.

368.60 Grounding. Busway shall be bdniaected to: an
feqiiipment growditig cotiductc)r(s)j to an equipjaiertt
boiiding jumper, or to the grounded conductor where
j^itted Of requjtM Jby :25O.92(®0 250. 142]

III. Construction

368.120 Marking. Busways shall be marked with the
voltage and current rating for which they are designed, and
with the manufacturer's name or trademark in such a
manner as to be visible after installation.

IV. Requirements for Over 600 Volts, Nominal
368.214 Adjacent and Supporting Structures. Metal-
enclosed busways shall be installed so that temperature rise
from induced circulating currents in any adjacent metallic
parts will not be hazardous to personnel or constitute a fire
hazard.

368.234 Barriers and Seals.

(A) Vapor Seals. Busway runs that have sections located
both inside and outside of buildings shall have a vapor seal
at the building wall to prevent interchange of air between
indoor and outdoor sections.

Exception: Vapor seals shall not be required in forced-
cooled bus.

2010 California Electrical Code

70-215

368.236

ARTICLE 370 ~ CABLEBUS

(B) Fire Barriers. Fire barriers shall be provided where
fire walls, floors, or ceilings are penetrated.

FPN: See 300.21 for information concerning the spread of

fire or products of combustion.

368.236 Drain Facilities. Drain plugs, filter drains, or
similar methods shall be provided to remove condensed
moisture from low points in busway run.

368.237 Ventilated Bus Enclosures. Ventilated busway
enclosures shall be installed in accordance with Article
no, Part III, and 490.24.

368.238 Terminations and Connections. Where bus
enclosures terminate at machines cooled by flammable gas,
seal-off bushings, baffles, or other means shall be provided
to prevent accumulation of flammable gas in the busway
enclosures.

All conductor termination and connection hardware
shall be accessible for installation, connection, and
maintenance.

368.239 Switches. Switching devices or disconnecting
links provided in the busway run shall have the same
momentary rating as the busway. Disconnecting links shall
be plainly marked to be removable only when bus is de-
energized. Switching devices that are not load-break shall
be interlocked to prevent operation under load, and
disconnecting link enclosures shall be interlocked to
prevent access to energized parts.

368.240 Wiring 600 Volts or Less, Nominal. Secondary
control devices and wiring that are provided as part of the
metal-enclosed bus run shall be insulated by fire-retardant
barriers from all primary circuit elements with the
exception of short lengths of wire, such as at instrument
transformer terminals.

368.244 Expansion Fittings. Flexible or expansion
connections shall be provided in long, straight runs of bus
to allow for temperature expansion or contraction, or where
the busway run crosses building vibration insulation joints.
368.258 Neutral Gpnduciori Neutral bus, where required,
shall be sized to carry all neutral load current, including
harmonic currents, and shall have adequate momentary and
short-circuit rating consistent with system requirements.
368.260 Grounding. Metal-enclosed busway shall be
grounded.

368.320 Marking. Each busway run shall be provided
with a permanent nameplate on which the following
information shall be provided:

(1) Rated voltage.

(2) Rated continuous current; if bus is forced-cooled, both
the normal forced-cooled rating and the self-cooled
(not forced-cooled) rating for the same temperature
rise shall be given.

(3) Rated frequency.

(4) Rated impulse withstand voltage.

(5) Rated 60-Hz withstand voltage (dry).

(6) Rated momentary current.

(7) Manufacturer's name or trademark.

FPN: See ANSI C37.23-1987 (R1991), Guide for Metal-
Enclosed Bus and Calculating Losses in Isolated-Phase
Bus, for construction and testing requirements for metal-
enclosed buses.

■ ARTICLE 370

370.1 Scope. This article covers the use and installation
requirements of cablebus and associated fittings.

370.2 Definition.

Cablebus. An assembly of insulated conductors with
fittings and conductor terminations in a completely
enclosed, ventilated protective metal housing. Cablebus is
ordinarily assembled at the point of installation from the
components furnished or specified by the manufacturer in
accordance with instructions for the specific job. This
assembly is designed to carry fault current and to withstand
the magnetic forces of such current.

370.3 Use. Approved cablebus shall be permitted at any
voltage or current for which spaced conductors are rated
and shall be installed only for exposed work, except as
permitted in 370.6. Cablebus installed outdoors or in
corrosive, wet, or damp locations shall be identified for
such use. Cablebus shall not be installed in hoistways or
hazardous (classified) locations unless specifically
approved for such use. Cablebus shall be permitted to be
used for branch circuits, feeders , and services.

Cablebus framework, where bonded, shall be
permitted to be used as the equipment grounding conductor
for branch circuits and feeders.

370.4 Conductors.

(A) Types of Conductors. The current-carrying
conductors in cablebus shall have an insulation rating of
75°C (167°F) or higher and be an approved type suitable
for the application.

(B) Ampacity of Conductors. The ampacity of conductors
in cablebus shall be in accordance with Table 310.17 and
Table 310.19, or with Table 310.69 and Table 310.70 for
installations over 600 volts.

(C) Size and Number of Conductors. The size and
number of conductors shall be that for which the cablebus
is designed, and in no case smaller than 1/0 AWG.

(D) Conductor Supports. The insulated conductors shall
be supported on blocks or other mounting means designed
for the purpose.

The individual conductors in a cablebus shall be
supported at intervals not greater than 900 mm (3 ft) for
horizontal runs and 450 mm (Wi ft) for vertical runs.
Vertical and horizontal spacing between supported
conductors shall not be less than one conductor diameter at
the points of support.

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2010 California Electrical Code

ARTICLE 372 - CELLULAR CONCRETE FLOOR RACEWAYS

372.2

370.5 Overcurrent Protection. Cablebus shall be
protected against overcxirrent in accordance with the
allowable ampacity of the cablebus conductors in
accordance with 240.4.

Exception: Overcurrent protection shall be permitted in
accordance with 240 J 00 and 240.101 for over 600 volts,
nominal

370.6 Support and Extension Through Walls and
Floors.

(A) Support. Cablebus shall be securely supported at

intervals not exceeding 3.7 m (12 ft).

Exception: Where spans longer than 5.7 m (12 ft) are
required, the structure shall be specifically designed for the
required span length.

(B) Transversely Routed. Cablebus shall be permitted to
extend transversely through partitions or walls, other than
fire walls, provided the section within the wall is
continuous, protected against physical damage, and
unventilated.

(C) Through Dry Floors and Platforms. Except where
firestops are required, cablebus shall be permitted to extend
vertically through dry floors and platforms, provided the
cablebus is totally enclosed at the point where it passes
through the floor or platform and for a distance of 1.8 m (6
ft) above the floor or platform.

(D) Through Floors and Platforms in Wet Locations.

Except where firestops are required, cablebus shall be
permitted to extend vertically through floors and platforms
in wet locations where (1) there are curbs or other suitable
means to prevent waterflow through the floor or platform
opening, and (2) where the cablebus is totally enclosed at
the point where it passes through the floor or platform and
for a distance of 1 .8 m (6 ft) above the floor or platform.

370.7 Fittings. A cablebus system shall include approved
fittings for the following:

(1) Changes in horizontal or vertical direction of the run

(2) Deadends

(3) Terminations in or on connected apparatus or
equipment or the enclosures for such equipment

(4) Additional physical protection where required, such as
guards where subject to severe physical damage

370.8 Conductor Terminations. Approved terminating
means shall be used for connections to cablebus
conductors.

370.9 Grounding. A cablebus installation shall be
grounded and bonded in accordance with Article 250,
excluding 250.86, Exception No. 2.

370.10 Marking. Each section of cablebus shall be
marked with the manufacturer's name or trade designation
and the maximum diameter, number, voltage rating, and
ampacity of the conductors to be installed. Markings shall
be located so as to be visible after installation.

CeUular Concrete JTjppr

372.1 Scope. This article covers cellular concrete floor
raceways, the hollow spaces in floors constructed of
precast cellular concrete slabs, together with suitable metal
fittings designed to provide access to the floor cells.

372.2 Definitions.

Cell. A single, enclosed tubular space in a floor made of
precast cellular concrete slabs, the direction of the cell
being parallel to the direction of the floor member.

Header. Transverse metal raceways for electrical
conductors, providing access to predetermined cells of a
precast cellular concrete floor, thereby permitting the
installation of electrical conductors from a distribution
center to the floor cells.

372.4 Uses Not Permitted. Conductors shall not be
installed in precast cellular concrete floor raceways as
follows:

(1) Where subject to corrosive yapor

(2) In any hazardous (classified) location, except as
permitted by ^§^^-M^^^M.^^M^

(3) In commercial garages, other than for supplying ceiling
outlets or extensions to the area below the floor but not
above

FPN: See 300.8 for installation of conductors with other
systems.

372.5 Header. The header shall be installed in a straight
line at right angles to the cells. The header shall be
mechanically secured to the top of the precast cellular
concrete floor. The end joints shall be closed by a metal
closure fitting and sealed against the entrance of concrete.
The header shall be electrically continuous throughout its
entire length and shall be electrically bonded to the
enclosure of the distribution center.

2010 California Electrical Code

70-217

372.6

ARTICLE 374 - CELLULAR METAL FLOOR RACEWAYS

372.6 Connection to Cabinets and Other Enclosures.

Connections from headers to cabinets and other enclosures
shall be made by means of listed metal raceways and listed
fittings.

372.7 Junction Boxes. Junction boxes shall be leveled to
the floor grade and sealed against the free entrance of water
or concrete. Junction boxes shall be of metal and shall be
mechanically and electrically continuous with the header.

372.8 Markers. A suitable number of markers shall be
installed for the future location of cells.

372.9 Inserts. Inserts shall be leveled and sealed against
the entrance of concrete. Inserts shall be of metal and shall
be fitted with grounded-type receptacles. A grounding
conductor shall connect the insert receptacles to a positive
ground connection provided on the header. Where cutting
through the cell wall for setting inserts or other purposes
(such as providing access openings between header and
cells), chips and other dirt shall not be allowed to remain in
the raceway, and the tool used shall be designed so as to
prevent the tool from entering the cell and damaging the
conductors.

372.10 Size of Conductors. No conductor larger than 1/0
AWG shall be installed, except by special permission.

372.11 Maximum Number of Conductors. The

combined cross-sectional area of all conductors or cables
shall not exceed 40 percent of the cross-sectional area of
the cell or header.

372.12 Splices and Taps. Splices and taps shall be made
only in header access units or junction boxes.

For the purposes of this section, so-called loop wiring
(continuous unbroken conductor connecting the individual
outlets) shall not be considered to be a splice or tap.

372.13 Discontinued Outlets. When an outlet is
abandoned, discontinued, or removed, the sections of
circuit conductors supplying the outlet shall be removed
from the raceway. No splices or reinsulated conductors,
such as would be the case of abandoned outlets on loop
wiring, shall be allowed in raceways.

372,17 Ampacity of Conductors. The ampacity
adjustment factors, provided in 310.15(B)(2), shall apply to
conductors installed in cellular concrete floor raceways.

;.|:ARTICtE:3j4^^
CeUular McJtai FlcMi^R^cew

374.1 Scope. This article covers the use and installation
requirements for cellular metal floor raceways.

374.2 Definitions.

Cellular Metal Floor Raceway. The hollow spaces of
cellular metal floors, together with suitable fittings, that
may be approved as enclosures for electrical conductors.

Cell A single enclosed tubular space in a cellular metal
floor member, the axis of the cell being parallel to the axis
of the metal floor member.

Header. A transverse raceway for electrical conductors,
providing access to predetermined cells of a cellular metal
floor, . thereby permitting the installation of electrical
conductors from a distribution center to the cells.

374.3 Uses Not Permitted. Conductors shall not be
installed in cellular metal floor raceways as follows:

(1) Where subject to corrosive vapor

(2) In any hazardous (classified) location, except as
permitted by other attiotes in this: Gc?<fe

(3) In commercial garages, other than for supplying
ceiling outlets or extensions to the area below the
floor but not above

FPN: See 300.8 for installation of conductors with other
systems.

I. Installation

374.4 Size of Conductors. No conductor larger than I/O
AWG shall be installed, except by special permission.

374.5 Maximum Number of Conductors in Raceway.

The combined cross-sectional area of all conductors or
cables shall not exceed 40 percent of the interior cross-
sectional area of the cell or header.

374.6 Splices and Taps. Splices and taps shall be made
only in header access units or junction boxes.

For the purposes of this secfion, so-called loop wiring
(continuous unbroken conductor connecting the individual
outlets) shall not be considered to be a spHce or tap.

374.7 Discontinued Outlets. When an outlet is
abandoned, discontinued, or removed, the sections of
circuit conductors supplying the outlet shall be removed
from the raceway. No splices or reinsulated conductors,
such as would be the case with abandoned outlets on loop
wiring, shall be allowed in raceways.

70-218

2010 California Electrical Code

ARTICLE 376 - METAL WIREWAYS

376.10

374.8 Markers. A suitable number of markers shall be
installed for locating cells in the future.

374.9 Junction Boxes. Junction boxes shall be leveled to
the floor grade and sealed against the free entrance of water
or concrete. Junction boxes used with these raceways shall
be of metal and shall be electrically continuous with the
raceway.

374.10 Inserts. Inserts shall be leveled to the floor grade
and sealed against the entrance of concrete. Inserts shall be
of metal and shall be electrically continuous with the
raceway. In cutting through the cell wall and setting inserts,
chips and other dirt shall not be allowed to remain in the
raceway, and tools shall be used that are designed to
prevent the tool from entering the cell and damaging the
conductors.

374.11 Connection to Cabinets and Extensions from
Cells. Connections between raceways and distribution
centers and wall outlets shall be made by means of
liquidtight flexible metal conduit, flexible metal conduit
where not installed in concrete, rigid metal conduit,
intermediate metal conduit, electrical metallic tubing, or
approved fittings. Where there are provisions for the
termination of an equipment grounding conductor,
nonmetallic conduit, electrical nonmetallic tubing, or
liquidtight flexible nonmetallic conduit shall be permitted.
Where installed in concrete, Hquidtight flexible nonmetallic
conduit shall be listed and marked for direct burial.

FPN: Liquidtight flexible metal conduit and liquidtight
flexible nonmetallic conduit that is suitable for installation
in concrete is listed and marked for direct burial.

374.17 Ampacity of Conductors. The ampacity
adjustment factors in 310.15(B)(2) shall apply to
conductors installed in cellular metal floor raceways.

II. Construction SpeciHcations

374.100 General. Cellular metal floor raceways shaU be
constructed so that adequate electrical and mechanical
continuity of the complete system will be secured. They
shall provide a complete enclosure for the conductors. The
interior surfaces shall be free from burrs and sharp edges,
and surfaces over which conductors are drawn shall be
smooth. Suitable bushings or fittings having smooth
rounded edges shall be provided where conductors pass.

ARTICLE 376

Metal Wireways

I. General

376.1 Scope. This article covers the use, installation, and
construction specifications for metal wireways and
associated fittings.

376.2 Definition.

Metal Wireways. Sheet metal troughs with hinged or
removable covers for housing and protecting electrical
wires and cable and in which conductors are laid in place
after the wire way has been installed as a complete system.

II. Installation

376.10 Uses Permitted. The use of metal wireways shall
be permitted in the following:

(1) For exposed work

(2) In concealed spaces as permitted in 376.10(4)

(3) In hazardous (classified) locations as permitted by
501.10(B) for Class I, Division 2 locations; 502.10(B)
for Class II, Division 2 locafions; and 504.20 for
intrinsically safe wiring. Where installed in wet
locations, wireways shall be listed for the purpose.

(4) As extensions to pass transversely through walls if the
length passing through the wall is unbroken. Access to
the conductors shall be maintained on both sides of the
wall.

376.12 Uses Not Permitted. Metal wireways shall not be
used in the following:

(1) Where subject to severe physical damage

(2) Where subject to severe corrosive environments

376.21 Size of Conductors. No conductor larger than
that for which the wireway is designed shall be installed
in any wireway.

376.22 Number of Conductors and Ampacity. The

number of condqctors and their ampacity shall comply with

376.22(A)' and'^5 '

(A|) Crpis-Secti^^ of Wirewayj The sum of the

cross-sectional areas of all contained conductors at any
cross section of a wireway shall not exceed 20 percent of
the interior cross-secfional area of the wireway.

2010 California Electrical Code

70-219

376.12

ARTICLE 376 - METAL WIREWAYS

(§) ^i^mtmeii^"^fMCim$l, The adJustt^S factors in
310.15(B)(2)(a) shall be applied only where the number of
current-carrying conductors, including neutral conductors
classified as current-carrying under the provisions of
310.15(B)(4), exceeds 30. Conductors for signaling circuits
or controller conductors between a motor and its starter and
used only for starting duty shall not be considered as
current-carrying conductors. r

376.23 Insulated Conductors. Insulated conductors
installed in a metallic wireway shall comply with
376.23(A) and (B).

(A) Deflected Insulated Conductors. Where insulated
conductors are deflected within a metallic wireway, either
at the ends or where conduits, fittings, or other raceways or
cables enter or leave the metallic wireway, or where the
direction of the metallic wireway is deflected greater than
30 degrees, dimensions corresponding to one wire per
terminal in Table 312.6(A) shall apply.

(B) Metallic Wireways Used as Pull Boxes. Where
insulated conductors 4 AWG or larger are pulled through a
wireway, the distance between raceway and cable entries
enclosing the same conductor shall not be less than that
required by 314.28(A)(1) for straight pulls and
314.28(A)(2) for angle pulls. When transposing cable size
into raceway size, the minimum metric designator (trade
size) raceway required for the number and size of
conductors in the cable shall be used.

376.30 Securing and Supporting. Metal wireways shall
be supported in accordance with 376.30(A) and (B).

(A) Horizontal Support. Wireways shall be supported
where run horizontally at each end and at intervals not to
exceed 1.5 m (5 ft) or for individual lengths longer than 1.5
m (5 ft) at each end or joint, unless listed for other support
intervals. The distance between supports shall not exceed 3
m(lOft).

(B) Vertical Support. Vertical runs of wireways shall be
securely supported at intervals not exceeding 4.5 m (15 ft)
and shall not have more than one joint between supports.
Adjoining wireway sections shall be securely fastened
together to provide a rigid joint.

376.56 Splices, Taps, and Power Distribution Blocks.

(A) Splices and Taps. Splices and taps shall be permitted
within a wireway, provided they are accessible. The
conductors, including splices and taps, shall not fill the
wireway to more than 75 percent of its area at that point.

(B) Power Distribution Blocks.

(1) Installation. Power distribution blocks installed in
metal wireways shall be listed.

(2) Size of Enclosure. In addition to the wiring space
requirement in 376.56(A), the power distribution block
shall be installed in a wireway with dimensions not smaller
than specified in the installation instructions of the power
distribution block.

(3) Wire Bending Sp